Rehva Journal Magazine issue 1/2013
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Rehva Journal nr.1/2013

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Rehva Journal Magazine issue 1/2013 Rehva Journal Magazine issue 1/2013 Document Transcript

  • REHVA The REHVA Federation of European HVAC Journal European Heating, Ventilation and Air Conditioning V o l u m e :  5 0 I s s u e :  1 J a n u a r y  2 0 1 3 w w w. rehva .eu AssociationsSpecial issue onAIRTIGHTNESSHow to make airtight buildingsEffect of envelope airtightnesson energy useSummary of AIVC TightVentConferenceDuctwork tightness:Swedish and Portuguese experience
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  • The REHVA www.rehva.euEuropean HVAC Journal ContentsVolume: 50 Issue: 1 January 2013 Editorial 47 A new innovative Ground Heat Exchanger forRehva Board heating, cooling and energy storagePresident: Michael Schmidt 5 Building and ductwork airtightness: a critical John Ljungqvist, Thomas Vogel and Lars Nielsen factor for nearly zero-energy buildingsPresident elect: Karel Kabele François Rémi Carrié and Peter Wouters 50 Improved energy efficiency of air cooledVice Presidents: chillersStefano Corgnati Articles Maurizio BurbaIoan Silviu DobosiJarek Kurnitski 6 Summary of the AIVC-TightVent NewsZoltán Magyar Conference 2012Bjarne W. Olesen Ventilation and Health track 54 Eco design of energy related products Willem de Gids 7 – time for industry to wake upEditorial Board - 2013 Jorma RailioFrancis Allard, France Ventilative Cooling trackAhmet Arısoy, Turkey 56 Substantial benefits of cogeneration to Per Heiselberg 9Jan Aufderheijde, the Netherlands European economyDerrick Braham, UK Airtightness trackMarianna Brodatch, Russia Arnold Janssens 11 57 National energy efficiency policies in EU: Vincenc Butala, Slovenia The view of 750 expertsFrancesca R. d’Ambrosio, Italy 14 Interview: Industry visions on R&D for betterIoan Silviu Dobosi, Romania buildings in the future 64 Indoor environment in the focus of the 10thSignhild Gehlin, Sweden Ventilation Conference in ParisJaap Hogeling, the Netherlands 17 Proper building preparation for envelopeKarel Kabele, Czech Republic Guangyu Cao and Aimo TaipaleJarek Kurnitski, Estonia airtightness testingZoltán Magyar, Hungary Christophe Delmotte Product newsEduardo Maldonado, Portugal 20 Performing intermediate checks and early- 66 Zephir³ by Clivet: air renewal and purificationLivio Mazzarella, ItalyRenato Merati, Italy stage testing of airtightness at the centre of year round comfort andBjarne W. Olesen, Denmark Tormod Aurlien energy savings in the new and existingDušan Petráš, Slovakia buildingsMichael Schmidt, Germany 24 Research into the effect of improvingOlli Seppänen, Finland airtightness in a typical UK dwelling 67 Window installation system for projectingJerzy Sowa, Poland windows Rob CoxonBranislav Todorovic, Serbia 68 The MEZ air duct profile complies with leakMaija Virta, Finland 28 Swedish experience with airtight ductwork tightness classes C and D Johnny AnderssonGeneral Executive: Süleyman Bulak 69 Increased energy efficiency with TELLUS 33 Ductwork airtightness requirements in Climate system from SwegonEditor-in-chief: Olli Seppänen 70 BlowerDoor Measuring Systems feature high Eduardo Maldonado and Fernando BritoAssociate Editor: Stefano Corgnati, Italy and consistent 36 Evaluation of air leakage and its influenceEditorial Assistant: Cynthia Despradel on thermal demands of office buildings in 70 Infitrometer from RetrotecGuest Editors:   MadridRémi Carrié and Peter Wouters Books Jordi Pascual, Aleksandar Ivancic, MariaAIVC/INIVE 72 Review of the REHVA Guidebook No. 17 Casanova, Oscar Cámara and Damien Tavan ‑ Design of energy efficient ventilation andAdvertisements 41 Energy efficiency strategy at the portfolio ofMs Cynthia Despradel air conditioning a property Yona Kamelgarn and Frank Hovorka 74 Events in 2013 – 2014Subscriptions andChanges of addressesREHVA OFFICE: AdvertisersWashington Street 401050 Brussels, BelgiumTel: 32-2-5141171, Fax: 32-2-5129062  Bitzer................ Front cover interior  Scanvac...................................... 59,  ISH Frankfurt.............................. 4  Friterm....................................... 63Publisher  Blower Door GmbH.................. 10  Swegon....................................... 71Sektorel Fuarcılık A.Ş (Inc.)  Hitema....................................... 13  ACREX 2013.... Back cover interiorBalmumcu, Barbaros Bulvarı,Bahar Sok, Karanfil Ap.  AHRI......................................... 23  REHVA Supporters........Back coverBeşiktaş İstanbul TürkiyeTel: 90-212-2758359Fax: 90-212-2749273 In the next issue of REHVA Journalwww. teknikyayincilik.comREHVA Journal is distributed in over 50 countries through the Theme: Air Conditioning and Ventilation. .Member Associations and other institutions. The views expressed Guest Editor: Zoltan the Journal are not necessarily those of REHVA or its members.REHVA will not be under any liability whatsoever in respect of Email: zmagyar@invitel.hucontributed articles. Send the manuscripts of articles for the journal to .Cover photo: © or to View slide
  • The world’s leading trade fair The Bathroom Experience, Building, Energy, Air-conditioning Technology Renewable EnergiesFrankfurt am Main12 – 16. 3. 2013 Energy Energy that moves the world. ISH is the world’s most important showcase for efficient building and energy technology in combination with renewable energies. Make sure you’re here to experience sustainable system solutions. Keep ahead of your competitors with ISH Frankfurt the latest information and benefit from new inspirations for your business. View slide
  • EditorialBuilding and ductwork airtightness: a critical factor for nearly zero-energy buildings Building and ductwork airtightness represents a key challenge for the François Rémi Carrié and Peter Wouters building sector. Guest editors, AIVC/INIVE T he 2002 Energy Performance of Buildings Directive (EPBD) already indicated the poten- tial importance of airtightness. With the 2010 EPBD recast and its ambitious 2020 tar- gets, there is even more pressure on these aspects since for most European climates and countries, good envelope and ductwork airtightness levels are necessary to achieve nearly zero-en- ergy buildings. Several studies report an energy impact of leaky buildings on the order of 10 kWh per m² of floor area per year for the heating needs in a moderately cold region (2 500 degree-days) and 0 to 5 kWh/ m²/year for the ducts plus the additional fan energy use. There is a growing number of studies show- ing the significant impact of building and ductwork leakage in hot and mild climates as well. The general consensus from these studies is that attention must be paid to building and ductwork air- tightness in nearly all climate regions of the European Union to meet nearly zero-energy targets. How do we achieve this in practice? First of all, building and ductwork airtightness has to be seen as a part of the building system. Legitimate concerns for energy efficient ventilation, comfort, skills development and market uptake must be considered in a holistic approach, addressing both new and existing buildings. There are promising signals with regard to the measures taken in several Member States to encourage better building and ductwork airtightness. For example, there are over 10 countries, covering all climate regions of Europe, with active (and usually very active) networks of professionals specialized in airtightness issues. Also, the steps taken by some Member States to improve building and ductwork airtightness, including actions on regulation, financial incentives, training, control and awareness raising, look promising. In 2011, the TightVent Europe platform ( was launched with a strong focus on market change in airtightness. The large number of attendees at the two last AIVC-TightVent conferences, as well as the large range of countries and issues addressed during these conferences, linking airtightness, comfort, indoor air quality and market transformation, show the growing in- terest in this topic. The 2012 AIVC-TightVent conference, held in Copenhagen, included three tracks specifically fo- cussed on airtightness, ventilative cooling, and indoor air quality and health. As can be seen from the summaries presented in this issue, as well as from the initiatives presented by experts from vari- ous Member States, the route towards nearly zero-energy buildings has many challenges, but it is also a unique opportunity to investigate new paths for product development, construction methods, commissioning, and building operations. To seize this opportunity, the building sector needs to be both creative and reactive: sharing experience and knowledge is surely key to meet this need. REHVA Journal – January 2013 
  • Articles Over 160 persons attended the joint ’33rd AIVC Conference‘ and ’2nd TightVent Conference’ in Copenhagen, on 10-11 October, 2012. Photo: OS Summary of the AIVC-TightVent Conference 2012 Optimising Ventilative Cooling and Airtightness for Nearly Zero-Energy Buildings, IAQ and Comfort T he conference focused on ventilation and infiltra- The conference was organized by the International Network tion in nearly zero-energy buildings and more par- on Ventilation and Energy Performance (INIVE) on behalf ticularly on challenges and perspectives for venti- of the Air Infiltration and Ventilation Centre (AIVC) and lative cooling (the use of ventilation systems to cool indoor TightVent Europe (the Building and Ductwork Airtightness spaces), on the rationale and solutions for better building Platform) with support from the VELUX group. and ductwork airtightness, as well as on developments of ventilation requirements based on health. The programme Per Heiselberg, Willem de Gids, and Arnold Janssens included presentations of invited world-renowned and key give here below a summary of the three tracks. experts as well as 75 papers selected from the call for ab- stracts for long- and short-oral presentations. Visit or for additional information. Next AIVC conference will be in Athens, Greece, 25−26 September 2013. It will be organised in conjunction with the   1st Venticool conference and the 3rd TightVent conference. More information will be soon available at REHVA Journal – January 2013
  • Articles Ventilation and Health track Willem de Gids The ventilation and health related presentations and papers on the 33rd AIVC con- VentGuide, the Netherlands ference were very interesting. We could learn a lot from these papers. Many were presented results of international projects/initiatives such as: • HealthVent “Health-Based Ventilation Guidelines for Europe” • IAIAQ “Promoting actions for healthy indoor air” • EnVie “Co-ordination Action on Indoor Air Quality and Health Effects” • “Health and comfort in highly energy efficient buildings” Clear Up “Clear and resource efficient buildings for real life” This summary synthesizes the papers and describes what we can learn from them. It is not a classic overview of papers but more a vision paper for future developments.Why we ventilate? tilation levels. On the other hand, ventilation can sig-Ventilation is often seen as the ultimate solution to all nificantly affect comfort, health risks, damp problemskind of indoor air quality problems. However venti- and performance of people in buildings.lation is not a panacea for all indoor air quality prob-lems: “just a little bit more ventilation and all problems Health, comfort and performance are the key aspectsare gone” does not always work. It is very clear that for ventilation.ventilation plays an important role in the control of ahealthy environment in buildings. But to understand In the built environment the existence of ventilation iswhen, where and how much ventilation is a necessity is in most cases based on dilution and mixing processes.a question which is not easy to answer. However, removing the unavoidable pollutant by local ex- traction is of course more effective. Displacement ventila-Let’s first of all look to the functions and effects of tion is the most effective mechanism to control ventilationventilation: flow and prevent from spreading of pollutants. Engineers often try to apply this so called “piston flow” mechanism, • Supply of oxygen for breathing to survive in because of its effectiveness. But in practice due to distur- buildings bances, for instance, moving people and buoyancy driven • Minimize exposure to hazardous contaminants to flows, it is difficult to maintain and realize the flow pat- reduce health risks terns we had in mind during the design process. • Minimize the nuisance of odors due to bio effluents to control comfort In the Ventilation and Health track, there were sessions • Dilution and transport of moisture to prevent organized around Health and Demand Controlled from damp problems Ventilation (DCV). Sometimes the results of the studies • Creation of an environment in which people can presented seem to conflict with each other. But analyz- perform in a optimal way ing the results more carefully, the conclusion appeared • Creation of an environment in which people feel to be that the results of the studies were more comple- thermally comfortable mentary than conflicting. The main reason for this is the time frame which was considered in the studies, forThe supply of oxygen, although an absolute necessity, is instance short term exposure (a few hours) versus longnot an issue in buildings with the normally realized ven- term exposure (a few years) REHVA Journal – January 2013 
  • Articles Most important pollutants indoors “What determines the ventilation flow at a certain From the most leading international studies, it looks moment on a certain or specific place?” like that the main important pollutants which effect our health indoors are: For short term health effects for instance due to expo- sure of formaldehyde, which cause eye and throat irrita- 1. tobacco smoke (ETS) tions an immediate level of ventilation is required. For 2. ultra fine particles (UFP) long term health effects (exposure during years) such as 3. acrolein (unsaturated aldehyde) long term exposure to formaldehyde at very low concen- 4. formaldehyde tration a yearly average ventilation of a certain ventila- 5. benzene tion level may the answer. Looking at moisture behav- 6. naphthalene ior in buildings, the processes of condensation, absorp- 7. carbon tetra chloride tion, desorption and evaporation in relation to building 8. NOx fabric and furniture are typically processes of a number 9. ozone of hours so that diurnal average ventilation might be 10. radon sufficient. For all these pollutants the general rule is: control the Looking into the performance of people in most cases source therefore minimize their presence in the indoor again an immediate level of ventilation is required to environment. Only for that part of these pollutants perform well. which can be considered as unavoidable the exposure can be minimized with ventilation means. The time frame, the moment, the reason why one will ventilate gives the answer to the question what is the ETS can be seen as an avoidable source in some build- dominant pollutant at a certain moment on a certain ings, while for instance radon should be minimized in place. Demand controlled ventilation in future should most cases by special measures and not specifically and develop its control algorithms and control sensors in only by ventilation. line with this view. In the field of CO2 and VOC sensor control, some papers indicate that much progress has Carbon dioxide (CO2) is not mentioned as an impor- been made over the last years on sensor technology and tant pollutant at all, because it is a marker for bio-efflu- sensor development. ents of people. The level of CO2 can be related to nui- sance of odor. This was established since Pettenkofer in Disability Adjusted Life Years 1860 the basis for almost all ventilation requirements in Many studies in this 33rd AIVC conference have tried to buildings. Later Yaglou, Cain and Fanger were under- find a single expression of the effect ventilation might lying this “odor nuisance driven” ventilation approach. have on health. More and more common becomes the Odor nuisance has not much to do with health, it is expression DALY, Disability Adjusted Life-Years. The comfort driven. DALY is more and more used as an indicator for health. It combines in fact three aspects: There are also recent studies indicating that CO2 it- self might of influence to the cognitive performance of • life expectancy people. In case the performance of people is the most • quality of life important parameter in rooms such as classrooms, lec- • number of people effected ture-rooms and even in some cases offices, CO2 levels should determine more the ventilation level than nui- With the aid of the metric DALY, all kind of decision sance and/or comfort. can be made more objectively also in combination with cost on the basis of cost effectiveness. When is ventilation needed and at what level? Several speakers reported that, only for Europe, around This question is most important when discussing de- 2.2 million DALYs/year are related to the indoor air mand controlled ventilation. The only answer can quality in buildings. We can make progress in minimiz- be: It depends on the specific effect you are ventilat- ing this problem by controlling the indoor air quality. ing for on the place of consideration. The important Ventilation may contribute to that in a significant way question is: in case we find effective solutions. REHVA Journal – January 2013
  • Articles Ventilative Cooling track The current development in building energy efficiency towards nearly-zero energy buildings represents a number of new challenges to design and con- struction of buildings. One of the major new challenges is the increased need for cooling present in these highly insulated and airtight buildings, which is not only present in the summer period but also in the shoulder seasons and in offices even during occupied hours in winter. In most post-occupancy studies of high performance buildings in European countries elevated temperature levels is the most reported problem, especially in residences. These new challenges were strongly reflected in the programme of the 33rd Per Heiselberg AIVC conference where about 30 papers and presentations in 6 sessions Aalborg University, Denmark dealt with different issues related to ventilative cooling.Performance Criteria icant individual differences in the preferred air velocity,The first question to ask in the design of ventilative cool- which indicate that personal control is very systems is what are the performance criteria? What isconsidered as overheating and how can ventilative cooling Prediction Methodsbe a solution? Research on different strategies to offset of Prediction of energy use in residential buildings is of-warm sensation in high temperature conditions showed ten based on simplified monthly methods and is esti-that increased air velocities can compensate and ensure mated for the residence as a whole. Averaging the needcomfortable conditions at higher temperature levels and for cooling in both time and space underestimates thethat air fluctuations and turbulence intensity play an im- need for cooling. Excess heat in spaces exposed to solarportant role. But, the research results also showed signif- radiation is considered to be distributed fully to other Number of subjects choosing a certain velocity. [Giulio Cattarin et al.   AIVC Conference proceedings,   pp. 8-12, 2012]. REHVA Journal – January 2013 
  • Articles spaces and excess solar ra- diation during daytime is partly distributed to night time. Therefore, the need for cooling to ensure ac- ceptable temperature lev- els in all spaces will be higher in reality. The anal- ysis of the risk of overheat- ing is often based on the calculated cooling need. Unfortunately, there is no correlation between the cal- culated cooling need with The Nicosia Townhall where special façade vents were developed to realise these simplified methods ventilative cooling in the building. [Flourentzou et al. AIVC Conference and the number of hours proceedings, pp. 233-237, 2012] with elevated temperature levels. So, even if no cool- ing need is predicted and designers do not expect over- The outcome of the Ventilative Cooling track was that es- heating problems, the number of hours with elevated pecially for residences there is a need to improve both the temperature levels can be considerable. Several presenta- way we estimate the need and the performance of venti- tions dealt with these issues both from a more theoretical lative cooling as well as for development of new, off-the- approach analyzing the energy balance and heat trans- shelf and competitive technical solutions. fer processes within spaces in buildings but also differ- ent methods to predict Ventilative Cooling performance and the risk of overheating was presented. Case Studies A number of case studies on the application of ventila- tive cooling were presented. The case studies demon- strated ventilative cooling solutions both in residences, schools and shopping malls and in many situations con- siderable energy savings was obtained. Several of the case studies highlighted the need for devel- opment of new technical solutions. One example was in the new Nicosia Townhall, where it was concluded that Blower Door free cooling by night ventilation was the simplest strate- gy to keep comfortable temperatures, but using standard openings was not the best solution. In order to ensure bet- ter opening possibilities as well as protection from insects, dust and vandalism special façade vents were developed. Conclusion Ventilative cooling can be an attractive and energy effi- cient solution to avoid overheating of both new and ren- GmbH ovated buildings. Ventilation is already present in most buildings through mechanical and/or natural systems and it can both remove excess heat gains as well as increase air velocities and thereby widen the thermal comfort range. As cooling becomes a need also outside the summer pe- riod the possibilities of utilizing the cooling potential of low temperature outdoor air increases considerably..10 REHVA Journal – January 2013
  • Articles Airtightness track The airtightness track at the AIVC conference consisted of 29 presentations organ- ized in 7 sessions. In 3 sessions research work was presented dealing with various air- tightness related aspects as requested in the call for papers. In 4 sessions invited pres- entations and structured discussions were offered to give an overview of some specific conference topics: • Ductwork airtightness • Quality and building airtightness • Quality of domestic ventilation systems Arnold Janssens • Philosophy and approaches for building airtightness requirements Professor of Building Physics, Ghent University, Belgium In the following paragraphs a bird’s eye view is given of trends and conclusions that appeared in the presentations and discussions in the airtightness track.From airtightness requirements to tice and requires careful planning of the overall build-quality assurance ing process. Therefore a number of quality manage-A number of presentations showed experimental evi- ment and training schemes were presented in order todence of the fact that new buildings become increasingly master this process. Sweden has a long experience withmore airtight, compared to buildings built in previous the implementation of quality ductwork systems anddecades. This evolution is attributed to the strength- has included quality requirements in the AMA speci-ening of energy performance requirements, typical- fication guidelines, based on subsequent partial test-ly in European countries, and to innovations in con- ing. In France regulatory quality management processesstruction practice. According to the European Energy are operational for building airtightness compliance byPerformance of Buildings Directive (EPBD) the influ- constructors, based on self-declared testing of a sampleence of air infiltration on the energy use of a building is of the housing production. Control tests have showntaken into account when assessing the energy perform- that these schemes are very effective in achieving goodance. As a result, building designers pay more attention airtightness in practice (Figure 1). Good examples ofto airtightness in order to meet more severe energy per-formance requirements for new buildings. However, insome countries also explicit airtightness requirementsare set in order to prepare the market for a change to-wards ‘nearly zero energy buildings’. An example of thisapproach is the French RT2012 legislation, which re-quires the airtightness of all new residential buildings tobe tested in order to show compliance to legal limits.Several presentations showed that the specification ofairtightness requirements alone is not enough to achievegood building airtightness in reality. When no qualityframework is adopted, design intents for airtightnessare not systematically met because of flaws and varia-tions in workmanship. This was shown in a project inGreenland where a large number of identical flats in a Figure 1. Results of control tests showing effectivenessbuilding was tested and a standard deviation of 47% of French quality framework for building airtightnesswas reported. Creating airtight building envelopes en- compliance (85% compliance demanded, 89% compli-tails profound changes in design and construction prac- ance achieved). [Juricic et al.] REHVA Journal – January 2013 11
  • Articles certification schemes for craftsmen were given by FLiB in Germany (Fachverband Luftdichtheit im Bauwesen), with guidelines for selection and installation of air bar- Air Infiltration and rier systems. Ventilation Centre Air leakage testing and infiltration modelling In recognition of the significant impact of ven- When airtightness requirements become more severe, tilation on energy use, combined with concerns also fan pressurization equipment and testing proce- over indoor air quality, the International Energy dures to show compliance should allow to obtain relia- Agency (IEA) inaugurated the Air Infiltration and ble and repeatable test results. Several presentations were Ventilation Centre in 1979. The AIVC is one of dealing with these issues. For testing single apartments the annexes running under the ECBCS, Energy in multifamily buildings different experimental proce- Conservation in Buildings and Community dures exist, and it is not always clear what one is meas- Systems, which is one of the Implementing uring. A number of test results were presented quantify- Agreements of the IEA. The AIVC offers indus- ing the leakage distribution in apartments for different try and research organisations technical support purposes: eg to assess the transfer of pollution between aimed at optimising ventilation technology. It of- individual flats, or to assess the air leakage distribution fers a range of services and facilities, including ratio between internal and external partitions of apart- comprehensive database on literature standards, ments. A large-scale measuring campaign in high rise and ventilation data. AIVC also produce a se- residential buildings in South Korea revealed that inter- ries of guides and technical notes. The Centre nal walls between flats often show the highest leakage holds annual conferences and workshops. The (30-60% of total leakage). operating agent of the AIVC is INIVE eeig ( A better knowledge of the air leakage distribution over the building envelope is also important to come to a more reliable extrapolation of fan pressurization test re- sults at 50 Pa to air infiltration rates under natural driv- were presented addressing IAQ performance in airtight ing forces (and related heat losses). While this extrapo- houses. Although simulations showed that IAQ may im- lation is typically based on rules of thumbs (the ‘rule- prove with enhanced building airtightness, specifically of-20’) or simplified steady-state models (Normalized for exhaust ventilation systems where designed air trans- Leakage), advanced simulation studies were presented fer is reinforced, the IAQ and indoor humidity achieved to analyse the influence of uneven leakage distribution in airtight houses is sensitive to ventilation system design, and unsteady wind conditions on air infiltration rates. sizing and installation errors. Ultimately these studies should allow to develop more refined and accurate leakage models for infiltration heat However, some presentations discussed results of large- loss assessment in high performance buildings. scale field studies showing striking evidence that in- stallation quality of residential ventilation systems is IAQ and ventilation in airtight typically insufficient. This was the case for studies buildings performed in the Netherlands, Belgium and Estonia. The fact that new buildings become more airtight is good Common shortcomings were insufficient supply ven- news for the energy performance of buildings, but is also tilation capacity compared to design standards (in a reason for concern when indoor air quality and health more than half of the investigated houses, Figure 2), issues are considered. In countries where residential ven- increased noise levels in case of mechanical ventila- tilation traditionally relied on air leakage and on occa- tion systems, and poor operation and maintenance. sional opening of windows, such as in New Zealand, it An overall conclusion was that together with increased is now found necessary to introduce reliable ventilation building airtightness, more attention should be paid solutions to achieve acceptable IAQ and moisture con- to ventilation system performance and installation trol in new airtight houses. Even in countries where the quality, in order to guarantee healthy indoor environ- installation of residential ventilation systems is part of the ments. This requires a change of mind set, not only building code requirements, such as in most European with building practitioners, but also with builders who countries, acceptable indoor air quality is not necessar- should be more willing to pay the price for good qual- ily achieved. A number of multizone simulation studies ity ventilation systems.12 REHVA Journal – January 2013
  • Articles Living room Master bedroom Other bedrooms 1.4 1.4 1.4 Air supply rate [l/s per m²] Air supply rate [l/s per m²] Air supply rate [l/s per m²] 1.2 1.2 1.2 1.0 1.0 1.0 0.8 0.8 0.8 0.6 0.6 0.6 0.4 0.4 0.4 0.2 0.2 0.2 0.0 0.0 0.0 low medium high low medium high low medium high Setting of the control switch Setting of the control switch Setting of the control switch Figure 2. Air supply rates (average, P10 and P90) in the living room, master bedroom and other bedrooms in dwell- ings with balanced mechanical ventilation, at different control settings. The horizontal line gives the reference (minimum) level according to the Dutch Building Code (0.7 l/s/m2), (Boerstra et al.). References Boerstra A., J. Balvers, R. Bogers, R. Jongeneel, F. van Dijken. 2012. Juricic S., S. Charrier, F. Boithias, J. Bionier. 2012. Lessons learnt Residential ventilation system performance: outcomes of a from the regulatory quality management scheme in France. field study in the Netherlands. Proceedings of the 33rd AIVC Proceedings of the 33rd AIVC Conference and 2nd TightVent Conference and 2nd TightVent Conference, Copenhagen, Conference, Copenhagen, INIVE, 148-151. INIVE, 170-175. HVAC-Designs for Data Centers and Switch Rooms Total Load @ 4,5 MWCooling equipment with superior operational qualities and high performance levels!Energy Efficient Cooling Solutionscustomizable and meeting the specs of even the mostcomplex installation Hitema We Manufacture Solutions! Hitema, Global Presence Advanced technology, absolute quality and closing at the Customer strong points that Hitema uses for its growth. Hitema is a Company that has shown competitive capacity and a big flexibility at Market requirements and it has been able to pay a leading role thanks to the ability to place good technological solution for industrial refrigeration, close control units and HVAC design for data center and switch rooms and compressed air treatment. Surely, determinated factors of our growth are the importance of the full satisfaction of the Customer and the various of the offer, with new products marked by Innovation and Quality.Inverter TechnologyCompressors - Total Load 3,2 Mw Z.I. San Gabriele – 35024 Bovolenta (Padova) - Italy Madrid - Spain Düsseldorf - Germany Tel.: +39 049 5386344 - Fax: +39 049 5386300 26 Feb - 01 Mar 2013 16 - 23 Oct 2013 E-mail: - Web page: Hall 6 - Stand 6D06 Hall 10 - Stand 10B76.5The ENGINEERED SOLUTION for FLEXIBILITY and PERFORMANCE REHVA Journal – January 2013 13
  • Articles Industry visions on R&D for better buildings in the future The programme of the 33rd AIVC Conference began with a panel discussion facilitated by Kirsten Engelund Thomsen from SBI, Denmark. REHVA Journal had an opportunity to have a short interview with the panellists, experts of leading companies in energy efficient technologies. REHVA Journal presented the following four questions to the experts: What challenges do you see for the next 10 years (2020 objectives) and beyond (2050) in research and development in the building sector? What are to your mind the major barriers to innovation e.g., legislative issues, calculation methods, costs, etc.? What are the ways to explore to overcome the barriers? What would be your suggestions to improve the quality of works (e.g. training and qualification of craftsmen)? scarce public funds. One answer to that challenge is to activate the large sums accumulated in private founda- tions and pension funds throughout Europe. Mrs. Lone Feifer In terms of technology, the solutions are already here, Strategic Project Director but to meet the challenges of the future, we have to find VELUX Group a way to implement them in today’s buildings. In other words a public demand must be created. In that perspective it is important to not only focus on the energy efficiency of buildings, but to also se- It is a fact that most of the buildings that have al- cure a healthy and comfortable indoor climate with ready been built represent a very large part of our fresh air and daylight. One of the solutions is to pro- future building stock. So I first and foremost believe that mote the use and development of ventilative cooling it is important to keep a long-term focus on finding and in buildings. developing solutions that will ensure that the existing building stock lives up to the 2020 objectives and - fur- The implementation of a number of mechanical so- ther ahead - the goals for 2050. lutions like air conditioning is constantly increasing. Those are solutions that use a lot of energy and do not Renovation of the current building stock represents a necessarily provide the buildings with sufficient air qual- large economic potential and an enormous job creation ity. One of the major challenges is to secure that more potential. We are, however, faced with the challenge of environmentally and healthier solutions such as ventila-14 REHVA Journal – January 2013
  • Articlestive cooling is reflected in government regulations, pro- six experimental low-energy buildings that are used bymoted by the building industry and demanded by the ordinary people. The houses have demonstrated thepublic - the people who will be living in the low-energy benefits of such technologies as ventilative cooling.buildings of tomorrow. Through Model Home 2020 we learned that another One of the biggest barriers to create more sustain- benefit is that experimental building projects also en- able living in buildings is that promotion and im- courage creativity and innovation because the focus onplementation of the technology requires financing - fi- single technical values is redirected into looking at thenancing of theoretical studies, test buildings and usabil- building from more holistic and qualitative perspectives.ity tests. This is also why it is important to promote a This of course speaks highly for allowing a more experi-public awareness and demand for the solutions. mental approach in today’s building regulations.Building regulations also represent a barrier. Often they In my opinion we need to focus on promotingdo not allow new technology to be implemented and simple solutions based on good building physicsthey are often based or focused on quantitatively de- instead of over-complicated, maintenance-demandingsigned values instead of qualitative objectives. Strict systems.rules and a one-sided focus on minimising energy con-sumption can create major barriers to the development In addition to training of craftsmen, there should alsoof sustainable living in low-energy buildings. be increased focus on the installer’s ability to advise the private buyer to make the right choices. In the ideal First of all, we have to show and not only tell world the installers must have both relevant and up- about the need for new ways of building houses. dated knowledge on how to build low-energy buildingsIn the VELUX Group we’ve done this through the that also deliver a sufficient indoor climate with plentyproject Model Home 2020. In the project we’ve built of fresh air and daylight. a doubling of the existing renovation rate; and the ex- isting renovations are not focused on energy efficien- cy. This can only be done if new long-term financing mechanisms are put in place; such as the suggested “pay Claus Bugge Garn as you save” schemes. Rockwool These renovations will have to be done with craftsmen without expertise in energy efficiency; ventilation and indoor air quality; and with low education levels. By far most of the renovations will be done; without having a building engineer involved in optimizing the solutions. In Europe we have app. 200 million dwellings, and we are constructing app. 1 million new dwell- We thus need to develop standardized “fool-proof ” meth-ings per year (0.5% from total number). The new dwell- ods that can be installed by an untrained workforce.ings are mainly an expansion of the total building massand not a replacement of existing buildings. Even if we The biggest barrier to innovation in the Europeanfrom tomorrow only constructed nearly zero energy construction industry is probably building tra-buildings; we would not reduce the energy consumption ditions. The construction industry is a very conserva-in buildings; but only maintain it at the current level tive industry that do not “like to experiment”; espe- cially within the private home sector. Building invest-The focus, in order to fulfill 2020 and 2050 targets set ments are very high; and often a once in a lifetime de-by EU, thus have to be on how to make a deep renova- cision; and we thus do not like to experiment. Thistion of existing building stock. We need to deeply ren- combined with the rather low knowledge level in theovate app. 2.5 − 3% of our existing dwellings per year; construction industry; makes it very difficult to intro-equal to app. 6 − 9 million dwellings. This is more than duce innovations. REHVA Journal – January 2013 15
  • Articles History has shown that the most efficient way manner. The construction industry consists mainly of to control and change the constructions sector very small companies; and in general a rather un- is via legislation (building codes). It is expected trained workforce, often with language barriers due in the construction industry that a number of re- to many nationalities involved. quirements have to be fulfilled when construction a new building or when making a major renovation. In I believe that the best way to secure sufficient qualifi- general the construction sector strives to fulfill cations is by introducing authorization requirements requirements. for companies within the construction sector. Meaning that in order to bid for a construction job; the compa- There is no doubt that there is a strong need ny needs to have an authorization. In order to have this for training of craftsmen. The question is how- authorization; the company needs to document that ever how to get this training organized in an efficient the craftsmen have received sufficient training. technical equipment fit together and operate optimally in the building. • The contractor has to be educated and informed by the designer so that systems are installed as Lars-Åke Mattsson designed and operate as intended. Lindab Ventilation AB • The politicians should create the business environment such that it is advantageous to meet the environmental targets. The biggest barrier is the fact that supplier that has the cheapest product will win the project. The The challenge is very difficult and has a lot of system of procurement is often very complicated and approaches and a lot of stakeholders. The easi- many involved can make money on a project that is est part is to develop relevant products and systems right on the lowest limit of the regulation. that work and have a great impact on the energy con- sumption and at the same time gives an excellent in- The most important issue is knowledge, all the door air quality with productive, healthy and happy way from the house owner to the politicians and people. the whole building industry. To educate everyone can- not be done by a single company. This can only be done I see the following items as problems in the current. by clusters of organizations like AIVC, Tightvent, situation and challenges for the future improvements: REHVA, local branch organisations. • Building owners should have relevant The certification like LEED, BREEAM are quite new information on the consequences of their systems that enable the house owner to buy a house decisions so that the final building with its with a level of predefined requirements without being systems meets the expectations. an expert himself. • The current systems are not always sustainable and not based on life cycle cost analysis. Another idea is to change the way of procurement so • The building systems are not always easy to that the builder must take care of the operating costs operate, and may not operate on optimal way. the first five years or similar. • There must be an organisation that is able to maintain and service the system and takes the To improve the quality of the work is extremely responsibility of proper operation. difficult and has to be looked on from a holistic • If the system is broken there must be an view and see it all the way from school, and the educa- organisation that can help the building owner tion material to certified installers and certified compa- and reset the system. nies and associated salary systems. To make a reforma- • Designers have to have more responsibility on tion like this has to involve politicians, governmental the performance on system level so that that all school board, unions and employers confederation. 16 REHVA Journal – January 2013
  • Articles Proper building preparation for envelope airtightness testingProper building preparation is required before initiating an airtightness test. While this may seemsurprising, HVAC systems often account for the most difficult part of the work. Taking this intoconsideration at the design stage of HVAC systems, however, can make the preparation easier. Hence, defining the objective of the test is essential for Christophe Delmotte the operator who needs answers to practical questions: Head of Air Quality and Ventilation Laboratory Belgian Building Research Institute • What part of the building is to be tested? • What are the rules governing the test? • What are the intentional openings in the envelope of this part of the building? • What HVAC systems and other equipment areIntroduction present in this part of the building?When measuring the airtightness (or air permeability)of a building, there is a crucial question that needs to be All of this leads to the final question: What preparationaddressed before starting work: What is the objective does the building require?of the measurement? Preparation in standardsThis question, however, might be obscure for most peo- Preparation of the part of the building subject to theple and may need refinement. test (hereafter called “the building”) is specifically ad- dressed in ISO 9972:2006 [2] and EN 13829:2000 [1],There are various reasons why one could measure the where different methods are described depending onairtightness of a building: the purpose: • To check compliance with a building code or • Method A (test of a building in use); contract (e.g. n50 ≤ 2 h-1); • Method B (test of the building envelope); • To check the effectiveness of new construction • Method C (test of the building in use) (not details (compared with other details in other available in EN 13829). buildings); • To calculate the building’s energy performance; In the current revision of ISO 9972 [3], the third • To find and seal leaks; method is replaced by a ”free” method intended for • … specific purposes such as checking compliance with en- ergy performance regulations. It thus opens up the pos-There are also different parts of a building that can be sibility of preparing the building in accordance withtested: a national regulation while still complying with the standard. • The entire building; • The thermally insulated part of the building; A point in common with all three existing methods is • A new part of the building; that all doors and windows in the building envelope • One apartment in the building; must be closed. Another common point is the opening • All the apartments on a given floor; of all interconnecting doors within the building (note • A block of offices in a factory; that the present exception for cupboards and closets will • … probably be deleted in the revision of ISO 9972). REHVA Journal – January 2013 17
  • Articles Preparation of HVAC systems ly-mounted air transfer devices can be of great impor- In addition to these easily accessible openings and a tance, not only with regard to ventilation but also with number of secondary ones like post boxes or cat flaps, regard to the building’s airtightness. the main preparation work relates to HVAC systems. The same consideration could apply to smoke damp- First, all devices taking air from or removing air to the ers or shut-off dampers for ventilation systems, cooker outside must be turned off: heating systems with indoor hoods and open fires. air intake, mechanical ventilation and air conditioning systems, kitchen hoods, etc. Since test operators gener- When openings must be sealed for the test, their tight- ally are not HVAC engineers, instructions for operation ness depends on various factors: should be available if needed. • The skill and caution of the operator; It is important to understand that measuring a build- • The accessibility of the opening; ing’s airtightness involves pressurising or depressurising • Technique and material. the envelope typically at 50 to 100 Pa. Therefore meas- ures must be taken to avoid diverting combustion gases Remember that the highest pressure exerted on the or polluted air from their intended routes and venting building envelope during an airtightness test is ap- them instead into occupied spaces. proximately 100 Pa, which represents 10 kg/m². Thus, sealing works must be able to withstand this pressure. In some cases, e.g. when open gas boilers in apartments However, this is not always easy with large louvres for are connected to the same chimney, it might be neces- example (Figure 1). sary to turn off the boilers of all apartments in the build- ing, even if only one of them is being tested. Second, all intentional openings in the building enve- lope dedicated to HVAC systems must be treated ac- cording to the measurement method. The three possible treatments are closed, sealed or open (Table 1). Figure 1. When openings must be closed for the test, leaks in Sealing a large the closing system are taken into account in the glo- louvre can bal air leakage rate of the building. This means that the prove to be a choice of HVAC components such as closable external- difficult task. Table 1. Treatment of the intentional openings in function of the test method (ISO/CD 9972:2012 [3]). Classification of openings Method 1 Method 2 Method 3 Test of the Test of the building Test of the building for building in use envelope a specific purpose Ventilation openings for natural Closed Sealed Closed, sealed or open as ventilation specified Openings for whole building mechanical Sealed Sealed Closed, sealed or open as ventilation or air conditioning specified Openings for local mechanical ventilation Closed Sealed Closed, sealed or open as or air conditioning (intermittent use) specified Windows, doors and trapdoors Closed Closed Closed, sealed or open as specified Openings not intended   Closed Sealed Closed, sealed or open as for ventilation specified18 REHVA Journal – January 2013
  • ArticlesSealing the mechanical ventilation systems is often nec-essary. There are three options: • Sealing the air terminal devices; • Sealing the air intake and exhaust; • Sealing the main ducts. Figure 2. Rubber bladders can be use-Sealing the air terminal devices (ATDs) is often an easy ful for sealing ventila-job in single dwellings but can be very tedious in mul- tion ducts.ti-family buildings or in office buildings for example.The most often used technique consists of removing theATDs from the ducts and replacing them with rubberbladders (Figure 2). Alternatively ATDs can be sealedwith adhesive tape.Another option is sealing the air intake and exhaust vents,but this often requires access to the roof or the top of a Figure 3. Sealing thewall, which might entail specific security measures. main ducts just be- fore or after the airThe third option consists of sealing the main ducts just handling unit is anbefore or after the air handling unit (AHU). This, how- option, but it gener-ever, requires access to the inside of the ducts through ally requires disman-the AHU or a partial dismantling of the ducts, work tling the ducts.that cannot be done by the test operator (Figure 3).Proper inspection panels in these ducts might be veryuseful here.To eliminate the need to seal the ventilation systems,shut-off dampers could be installed in the air intakeand exhaust ducts. These of course should be suffi-ciently airtight when closed, in order not to degradethe results of the airtightness test. These damperswould also be useful when taking shelter in buildingsis necessary, e.g. in the case of a large-scale outdoorpollution release.It is also important to note that the airtightness of theventilation ducts can influence the results of a building’s Figure 4. Access hatches in chimney flues can be very use-airtightness test. During the test, air indeed could leak ful if the flues need to be sealed for the airtightness test.out of or into the ducts within the building envelope,and again leak into or out of the ducts outside the build-ing envelope. Sealing the ducts precisely where they go Referencesthrough the building envelope could avoid this prob- [1] EN 13829:2000 Thermal performance of buildings -lem, but it is generally not feasible in practice. Making Determination of air permeability of buildings - Fanthe ducts airtight is therefore recommended not only for pressurization method (ISO 9972:1996, modified).ventilation purposes. [2] ISO 9972:2006 Thermal performance of buildings -Chimney flues for boilers, air heaters or stoves are often Determination of air permeability of buildings - Fanopen (or even closed in the case of stoves) during the pressurization method.airtightness test of the building. They, however, could besealed if required for the test. In this case, access hatches [3] ISO/CD 9972:2012 Thermal performance of buildingsprimarily intended for soot removal can be very useful - Determination of air permeability of buildings - Fan(Figure 4). pressurization method. REHVA Journal – January 2013 19
  • Articles Performing intermediate checks and early-stage testing of airtightness Tormod Aurlien Professor Dept. of Mathematical Sciences and Technology, Norwegian University of Life Sciences Good building airtightness is now commonly re- garded as an important prerequisite for both good energy performances, user comfort and service life of most modern buildings. Builders want to avoid the surprise of a poor airtightness measurement result in the finished phase of a new building. Repairing documented air leaks can then be a very costly experience and a complicated process. This paper gives effective methods to overcome Photo: Tormod Aurlien this problem, by sharing some good experiences from the process of avoiding pitfalls and achiev- ing good airtightness of buildings. Early-stage testing Figure 1. Temporary “tent” made from plastic foil, with Performing intermediate checks and early-stage testing a (red) blower door mounted. The amount of air that of airtightness of the building envelope is becoming part is sucked out of the tent by the fan in the blower door of common practice in Norway. Locating and repairing equals the leaking air that pass through the details of the leaks is at this stage is usually a very cost-effective task. façade being tested. A person inside the tent may easily detect air-leak- ages in the facade by just feeling with his hand along joints and details in question, if the air pressure inside the tent is kept at a lower level than the outside (around 50 Pa). There are several approaches to early-stage testing: This picture is from a new large building with passive-house ambition (n50<0.6 h-1). TESTING REPRESENTATIVE SMALL PARTS OF and contractors may draw conclusions of good detailing, THE ENVELOPE: In large building projects one may if one reaches good levels of airtightness. In the opposite test representative parts of the envelope details that case, one may not draw too strict quantitative conclusions, have been completed early compared to the rest of the as some of the leaking airflow may come from the tent. project. The purpose of this is to gather experience that can be used further on other the parts of the project. TESTING ZONES: Another approach is to pressu- This test is also useful as an extra quality assurance of rize a zone. These zones are often volumes of the build- as-built design, details and description of workmanship ing that are supposed to be airtight from other zones issues. This is especially helpful when the builder is con- for other reasons too, like fire zones of a large building. fronted with building products or details that are new In early stages of this kind of a building project, extra to the firm or to the industry. preparations are often required to insure airtightness from the other zones. Just achieving a pressure differ- One method of doing this testing is by defining and ence by use of a fan (not needing to read the measured pressurizing a temporarily isolated representative zone, leakages), and using a thermography camera, the tech- as shown in the Figure 1. nician may detect problems that need to be fixed for the rest of the project. Figure 2 shows one example of In this case, one measures the leakages from the test zone, a practical issue that had not been thought about in the including leakages from the temporary “tent”. Designers design phase of the project: temporary anchoring of the20 REHVA Journal – January 2013
  • ArticlesFigure 2a. Thermography from inside of construction Figure 2b. Leaky wind barrier detail, from anchoring ofshown in next photo. the outside scaffolding (Photos: Tormod Aurlien).outside scaffolding. In this case, the design was imme- are readily detected in this stage, by just feeling with thediately changed for the rest of the building project, and hand, having an inside under-pressure through use ofthe already built part has been repaired. the measuring fan. Furthermore the repair of these leak- ages is very cheap and easy.WIND-TIGHT-LAYER TESTING: What seemslike a Norwegian speciality is our relatively new em- We know of three measurements in this early wind-phasis on testing detached and semi-detached houses in tight-stage being performed in the 80’s in Norway.early wind-tight-stage, often by using low-cost simpli- A later similar measurement that took place in 1998fied equipment. A very large part of our population lives caught great these houses, and small firms usually build them. An initiative from The Norwegian HomebuilderCommon experience from numerous airtightness meas- Association soon led to simplified equipment beingurements that have ended up with high air permeability designed and spread to the market of their memberslevels, shows that trying to repair leaks on the inside of- in the building industry (Figure 3).ten is nearly fruitless. A report often has thermogramspinpointing the leaks, but the technician only detects The initial philosophy was to just create a pressure dif-where the leakage airflow enters the inside of the build- ference between the building and the outside (exceed-ing, not its source. The source may be somewhere in the ing around 30 Pa and possible to feel by hand on foilsouter wind-tight layer. Once the air has leaked in fromthe outside, it is easily distributed through cavity con-structions that are filled with highly permeable insula-tion. As constructions have become thicker, often withthe vapour-barrier being placed at a defined distancefrom the surface materials, it has become increasinglymore challenging to detect the flow paths using infra- (Systemair) Small < 500 m3/hred cameras or other detection techniques. Medium 500 – 1 500 m3/h Large 1 500 – 3 000 m3/hA natural response to this has been to perform airtight- 300 – 1 500 m3/h @ 50 Pa @ 50 Pameasurements in the stage where the outer layer is com-plete, doors and windows are in place etc, but before in- Figure 3. Simplified Norwegian equipment for  sulation is placed from the inside and covered. Leakages airtightness measurement of smaller buildings. REHVA Journal – January 2013 21
  • Articles etc. being tight). If the craftsman using the fan failed to achieve any pressure difference across the wall, then his Figure 4. Norwegian job was to find the leaks and repair them, until a pressure wooden building could be detected. This simple approach was very good!. being in early-wind- The project caught on, and it soon evolved into having tight-stage. Wind- some quantified results coming out of the process too. break layers are of non­woven HDPE Response from craftsmen fabric. Some parts of Doing airtightness testing on a more regular basis has the wall have gypsum been met with a bit of scepticism by some building boards in addition, to firms. On the other hand, a very common reaction by reach fire resistance skilled craftsmen, is that they very much appreciate be- goals. ing valued for the effort that they put into good crafts- manship and reaching technical goals, like airtightness; not only being valued for their effort towards the aes- part of the building process may cause extra air-leak- thetic finish. It is nice being told in forehand in the ages to the buildings. Examples include ventilation project that measurements are planned, though. Being ducts being installed in a late phase, with little atten- given the tools to perform these checks by oneself is even tion to making penetrations airtight, or balconies be- nicer. This last point has been an important reason for ing mounted delayed in the building process, the im- development of the simplified-method testing: the pos- provised anchoring causing leaks. sibility for the builders to perform testing themselves. The conclusion is that early wind-tight-stage measur- An important additional argument for performing ing should be followed up by a finished-state measure- these simplified-method tests is that airtightness test- ment. The early wind-tight-stage measurement should ing requires being on site on exactly the right time in be recognized as a good insurance for the builder against the building process, when the level of completeness blunders or incidents causing trouble with the customer is just appropriate. Craftsmen dislike being stopped in a later stage. It also serves as a powerful tool in the in progression, having to wait for someone with the process of gathering experience to achieve the intended right equipment to come when they have the capac- level of airtightness, especially with unfamiliar process- ity to do it themselves. As an illustration, one might es, details and materials, and thereby becoming every- note that the early-stage measurement on the building day practice in a rapidly changing industry. shown in Figure 4 was performed a little bit too early; one balcony door was not mounted yet, the result of The level of measurement accuracy for the fans and oth- challenges in timing. er equipment used is not extremely important, when used in early stage measurements. The purpose of these The importance of final-state initial depressurisations is not data with high accuracy. measurement We must assume that the following final measurements Quite recently the airtightness of the whole building are carried out with sufficiently precise equipment. It is from which Figure 1 is shown was measured. In this equally important that competent users of the equip- case governmental funding for passive house activity, ment, who understand and perform this according to requiring airtightness measuring, was released based international standards, do these measurements. on the preliminary measurements from the tents. It could have been awkward, though, if the required CHANGE OF NORWEGIAN REGULATIONS: airtightness goals were not met in the final measure- 3rd party independent inspection of design and work- ment of the whole building. Fortunately, the final- manship for airtightness level is becoming mandatory state measurements met the ambitious goals. Both at the start of 2013 for most of the Norwegian new builder and customer were happy. buildings. It is going to be exiting to follow how this turns out and develops. Experience from several measurements in both early stage and in finished stage on the same building shows Measuring is being recognised as being needed to prove that one might end up with a poorer airtightness at this important quality: Detailed design is necessary, but the final stage compared with the early-stage-measure- not sufficient to reach targeted level of airtightness needed ments. In fact, many things happening during the late for low-energy buildings.22 REHVA Journal – January 2013
  • AHRI
  • Articles Research into the effect of improving airtightness in a typical UK dwelling The UK’s Airtightness testing & Measurement Association (ATTMA) is a trade body that represents the UK’s leading air-tightness testing and consultancy firms. Most of the work undertaken by these firms is for the builders of new housing and buildings, who are required to prove that they have achieved the required level of air-tightness in their buildings in order to satisfy Building Regulations. Experiment needed for reliable data Rob Coxon Airtightness testing & Measurement What is needed is more reliable evidence as to the posi- Association (ATTMA), UK tive impact that improved air-tightness can deliver in a typical UK building or dwelling, alongside an appropri- ately designed and controlled ventilation system. Aside of those whose at the extremely sceptical end of the I n England and Wales, it has been a requirement aforementioned spectrum, most building professionals, that all types of new buildings and dwellings have and indeed the general public would acknowledge the to be tested since 2006. Prior to this, most build- general principle that a less air-leaky building is likely ings were neither designed nor built with air-tightness to be more energy and carbon efficient, and more com- in mind; primarily because there was no requirement for fortable for the occupants (providing the ventilation is testing. Consequently it is generally accepted that older appropriate). However, the problem is the lack of a sense UK houses and buildings are on average quite ‘leaky’. of scale or quantity. Indeed, research conducted by the Building Research Establishment (BRE) over 10 years ago determined that With this in mind, in 2010 the ATTMA decided to at- a typical UK dwelling leaked at a rate of 11.48 m³, per tempt to provide some evidence by means of commis- m² of their external envelope, per hour at an air pressure sioning a research project by the BRE, who are them- differential (between inside and outside of the envelope) selves members of ATTMA and acknowledged experts of 50 Pa (see below). The minimum standard permissi- in air-tightness, but who are also unrivalled in their abil- ble under current UK Building Regulations is 10m³/(m². ity to undertake building performance research projects hr) @50 Pa, although usually in order to attain overall of this type. compliance with calculated CO2 limits, a far lower (bet- ter) figure has to be both specified and achieved. The brief given to BRE was to undertake research to demonstrate the impact on the space heating load in a Effect of envelope airtightness on typical UK dwelling that arises when the air-permeabil- energy use? ity of its external envelope is improved. For this purpose, A frequent point of discussion among ATTMA members is the BRE provided two of its purpose-built ‘test houses’, the fact that, set against this background of generally ‘leaky’ located on the BRE’s, Watford site. The two dwellings existing building and housing stock in the UK, there is an are largely identical mid-terrace houses situated side-by- opportunity to significantly improve the energy and carbon side, with construction details that are typical of mil- performance of our existing building and housing stock by lions of existing UK dwellings. means of simple, low-tech but effecting air-sealing meas- ures. The barrier to this seems to be in lack of awareness as to the extent of the benefits that can be realised by this The two dwellings in the approach. This is reflected in the range of attitudes that test are largely identical air-tightness specialists come up against amongst builders, mid-terrace houses situ- building inspectors and even building managers/owners; ated side-by-side, with ranging from some who regard air-tightness as being as construction details that fundamental and vital as weather-tightness to those who are typical of millions of regard it with apathy, scepticism or even hostility. existing UK dwellings.24 REHVA Journal – January 2013
  • ArticlesThe test methodology was that of whole-house co-heat- indoor and outdoor air temperature difference allows aning testing, the principle of which is described below. In estimation of the whole house heat loss coefficient.short, it is a method of accurately determining the ag-gregated thermal losses of an unoccupied building. The Since the tests were undertaken during winter, the roomtesting was undertaken by Mr Arron Perry and Mr Nigel air temperature in each house was controlled to a con-Waldron from BRE’s Building Technology Group over- stant temperature between 18 and 23°C using electricseen by Mr David Butler, between November 2010 and heaters so that an average temperature difference of be-March 2011. Air-permeability testing was provided by tween 10 and 20°C was maintained between room andJamie Best of Melin Consultants. outside air temperature.Test buildings and testing procedure Electric convector heaters were installed in the mainThe two similar houses were used in order to provide a rooms and were controlled on a zone basis by accu-‘control’. For each, the co-heating testing and analysis was rate proportional temperature controllers with remoteconducted in two phases: firstly with them both having temperature sensors located centrally in the zone at ap-an equally high average air-permeability, then secondly proximately 1.5 m above the floor. The electricity con-with one having its air-permeability left high, while the sumed by the fans was accounted for by including themother had its air-permeability made much lower by means in the metered heater supplies. One pulse output kWhof sealing up its fabric. Each “phase” of testing lasted sev- electricity meter (1 000 pulses per kWh) was providederal weeks in order to gather sufficient data for analysis. in each zone. To maintain an even temperature distri- bution throughout the houses, all internal doors wereAir permeability testing was used to determine the air- fully open and air circulation fans were used to mix thepermeability of each house at the beginning and end of internal air. The fans were installed on poles above eacheach testing phase. heater to prevent stratification and encourage air circu- lation without excessively high air speeds.Measured air permeability of test houses in the testphases 1 and 2. External air temperature was measured by a shielded sensor Phase 1   Phase 2   near the north elevation of the terrace. Solar irradiance was Air Permeability Air Permeability measured by a Kipp and Zonen pyranometer mounted on (m³/(m².hr) @50 Pa) (m³/(m².hr) @50 Pa) a weather mast on the north field area of the BRE site. House 1 15.60 15.60 House 2 15.78 4.88 In order to minimise unaccounted for heat gains and losses all external windows and doors and other open-The air-permeability levels for both houses were de- ings were closed and all electricity consuming appliancesliberately increased for the first phase of the testing in and lighting was switched off. Access to the houses wasorder to create a larger margin of measured improve- also restricted to an absolute minimum during the du-ment. This was done by the air-tightness tester deliber- ration of the co-heating tests.ately introducing holes into the external walls and ceil-ings of the houses until repeated air-permeability test- Electricity consumption, room air temperatures, externaling showed that both houses were exhibiting an air-per- air temperature and solar irradiance were continuouslymeability of between 15 and 16 (m³/(m².hr) @50 Pa). measured and recorded using battery powered data loggersThey then both subjected to co-heating testing to dem- (Eltek SQ1000) with a recording interval of 15 minutes.onstrate establish the baselines for each. A few weekslater, House 2 was sealed and tested down to just un- Solar heat gains were determined by analysing the meas-der 5 (m³/(m².hr) @50 Pa), while House 1 was left un- ured solar irradiance data using a simple window solar heatchanged. The measurement of heat loss then resumed, gain model. The window model took account of the win-with House 1 effectively acting as the ‘control’. dow glass area, orientation and glazing type. Raw solar ir- radiance measured at each house on a horizontal plane wasThe Co-heating Test Methodology apportioned to each vertical orientation using the fractionThe co-heating test is a practical method of determining of hourly CIBSE cooling load data on each orientationthe combined fabric and infiltration heat loss of an un- (CIBSE Guide A, Table 5.19 Solar cooling loads).occupied house. It involves electrically heating the hous-es to a constant indoor temperature. Correlation of the The calculated solar gains were added to the measuredmeasured electrical heat input and solar heat gains with electrical heating energy to determine the total heat input REHVA Journal – January 2013 25
  • Articles House 1: House 2: Indoor and outdoor temperature, and solar irradiation. during the test for both houses. necessary to maintain the specified mean internal air tem- Linear regression analysis yielded the following heat loss perature. The houses were assumed to have low / medium coefficients (with forced y-axis intercept of y=0): thermal mass and therefore it was assumed that the major- ity of solar heat gains received during a day and absorbed Heat loss coefficients calculated from the measures into the house fabric would be released to the house inte- heating energy use during the test phases 1 and 2. rior in the same 24 hours period. Therefore the correlation Phase 1   Phase 2   of heat input with mean internal and external air tempera- Heat Loss Coefficient (W/K) Heat Loss Coefficient (W/K) ture difference was assessed on a 24 hours or daily basis. House 1 146.6 to 181.3 House 2 151.5 to 179.4 105.0 to 116.3 Test results The room air temperature in each unit was controlled The difference between the lower and upper regression to a range of fixed temperature values using electric line coefficients for each data set is assumed to be the heaters so that an average temperature difference of at effect of wind speed. least 10°C was maintained between room and outside air temperature. Solar heat gains were determined by Their relative heat loss performances can be attributed analysing the measured solar irradiance data using a to almost entirely the difference in fabric air-perme- simple window solar heat gain model. ability as all other factors remained the same for both;26 REHVA Journal – January 2013
  • ArticlesHouse 1 – Total heatinput versus dT:House 2 – Total heatinput versus dT:Heat loss coefficientfor both houses withdifferent airtightnessof building envelope.Upper lines correspondthe permeability of15.78 and lower lines4.88 (m³/(m².hr) @50 Pa).in particular, the climatic conditions that they were ex- were remedially air-sealed from their current state (i.e.posed to during the testing phases. an average leakage rate of 11.5 m³/(m².hr) @50 Pa to a not unreasonable level of 5 m³/(m².hr) @50 Pa, thenThe overall conclusion was this: the reduction in heat one could expect to see an average saving in heating costsloss in House 2 resulting from the air leakage sealing of up to 15% over the life of the property.measures, corresponding to an improvement in air per-meability from 15.78 to 4.88 (m³/(m².hr) @50 Pa), was Obviously this saving is at risk of being eroded by occu-between 46.5 and 63.1 W/K, equivalent to between 31 pant behaviour and in particular by losses from ventila-and 35% reduction in heat loss. tion. Nonetheless, weighed against the relatively mini- mal one-off cost of locating and permanently sealing theATTMA argue that it is reasonable to assert that there air-leakage sites, the argument is compelling.exists a linear relationship between air-tightness andheat loss (assuming all other factors remain constant). AcknowledgmentTherefore, it would for example be reasonable to assert Much of the technical content of this article is takenthat an improvement in air-tightness from, say 11.5 to from the BRE’s Report number 271-943, “Co-heating5 m³/(m².hr) @50 Pa would yield a reduction in heat Tests on BRE Test Houses Before and After Remedialloss in the order of 15%. Therefore, if typical UK houses Air Sealing” By David Butler and Arron Perry. REHVA Journal – January 2013 27
  • Articles Swedish experience with airtight ductwork ignore the benefits of airtight duct systems. This has probably resulted in poor ductwork installations in a Johnny Andersson Technical director, Ramboll, Sweden large fraction of the building stock. In these countries, installation is probably often undertaken using conven- tional in situ sealing techniques (e.g. tape or mastic), and therefore the ductwork airtightness is very much dependent upon the workers’ skills. Why is it important to have a tight AMA – an old and reliable Swedish ductwork? system to ensure high quality ductwork Many studies have identified defective ventilation sys- Starting already 1950 – i.e. for more than 60 years back tems and insufficient airflows as a main reason for oc- in time – we have been using a quite unique quality as- currence of sick buildings - the supply air needed to surance system in Sweden covering all aspects of build- assure a good air quality should thus reach the areas ing and installation technologies. Practically all build- where it is needed and not disappear along its transport ings and their installations in Sweden are performed ac- through the building. cording to the quality requirements in the AMA speci- fication guidelines (General Material and Workmanship Duct systems account for a large fraction of the energy Specifications). These requirements are made valid when use in a building. This is further increased with a leaky they are referred to in the contract between the owner duct system. The supply air flow has to cover the sum of and the contractor. total nominal air flow and the leaking flow. With leaky ductwork this will lead to a considerable and costly in- The requirements for tight ventilation ductwork sys- crease of the needed fan power. tems were included in AMA already in the early sixties. Sweden has thus a long and unbroken tradition of de- There are several good reasons to reduce the air leaks manding and controlling tightness of ventilation duct- from ductwork: work. During this long period, since 1966, the AMA tightness requirements have been raised in tact with • Correct air flows to and from the rooms are technology improvements and increased energy costs. dimensioned to ensure that emissions and heat loads are kept within set values and that AMA is a tool for the employer (developer/future pro- air quality (AQ) and thermal quality (TQ) are prietor) to specify his demands on the new building acceptable. and its installations. It is a work of reference – you use • Duct leaks can result in disturbing noise. the parts that are relevant for your project by referring • When leaky supply and extract air ducts are to these parts in your building specification. As an em- installed above a false ceiling part of the air will ployer – you have to state what you want, check that you take the simplest way, from the supply duct get it, and be prepared to pay the price for it! direct to the extract duct without bothering to pass through the connected rooms. The requirements are based on accepted demands – the requirements are regularly updated in accordance with In spite of these good reasons to use tight ductwork technology development and (LCC-) costs. The tech- we found in two EU projects that designers, installers, nology development has probably to some extent been building managers and owners in some countries often influenced by the regularly increased AMA demands.28 REHVA Journal – January 2013
  • Articles 20 Leakage, L/(s,m²)Changes of the demands are prepared by a workinggroup and discussed with – and accepted by – building 10 8 8owners, contractors and consultants. The demands are C L4 A 4 4to be specified in measurable units and in such a way C L2that the tenderers and contractors understand them and 2 CL 12 Bare able to calculate a price. 1 C L6 0.8 CDuctwork airtightness demands in 0.4 C L3AMA 1966 – 1972 0.2 DIt started with the AMA version 1966 when two “tight-ness norms”, A and B, were defined. It was also request- 0.1 0.04ed by the contractor to spot-check the tightness in a 0.04minimum of 10 m² duct perimeter area. 0.02In AMA 1972 the requirements were transformed into 0.01two “tightness classes” A and B (same as the EUROVENT 40 80 100 200 400 800 1000 2000classes today). Class A was the basic requirement for Static pressure difference ∆p, Pathe complete duct system in the air handling system(i.e. including dampers, filters, humidifiers and heatexchangers). It was advised to raise the requirement to Figure 1. Comparison between European (Euroventmeet Class B when the system operates for more than and AMA) Tightness Classes A – D and American8 hours/day and the air is treated (cooling, humidifica- (ASHRAE) Tightness classes CL3, CL6 etc.tion, high class filters etc.).A ductwork system is not specified to be tight – insteadthe permissible leakage rate at a specified test pressure isstated as a tightness class – that is possible to measure! How is the tightness tested – and by whom?Tightness classes in Eurovent (AMA) Requirements and demands can be worthless unless theyA: lowest class; B: 3 times tighter than A; C: 9 times are controlled. AMA thus also states the demands andtighter than A, and D: 27 times tighter than A. The the requirements for tightness testing of the ductwork.tightness classes are defined by a leak factor in l/s, m². The leakage rate at a specified test pressure is stated –The AMA has 400 Pa as standard test pressure. See lines this is possible to measure! – and it is compared to thein Figure 1. permissible value for the prescribed tightness class.In the USA (ASHRAE) the classes are raised in steps This control is normally done by the contractor as a spotof two times tighter: CL48: lowest class, CL24: 2 times check where the parts to be checked are chosen by thetighter than CL48 and so on till CL3: 16 times tighter owner’s consultant. This is specified in AMA and thusthan CL48 (Figure 1). being a part of the contract (i.e. the cost for the test is normally included in the contract lump sum). AMA al-With the Swedish AMA version 1983 Tightness Class so states the first part of the ductwork to be tested to beC was added for round ductwork larger than 50 m² 10% of the total duct area for round duct systems andwhile Class B was required for round duct systems with 20% for rectangular ducts.a surface area smaller than 50 m² and also for rectan-gular ductwork. Class A, the lowest class, was only ac- The control of whether the leak factor value is accept-cepted for visible supply and exhaust ducts within the able is measured by the contractor normally under theventilated room. In AMA 1998 Tightness Class D was supervision of the owner’s consultant. The contractor isadded (D is 3 times tighter than Class C). The use was required to hand over a filled in and signed AMA pro-not specified. It is an optional requirement for larg- tocol to the circular duct systems and where leakage can lead tohazards. AMA 2007 raised the requirements still an- The tightness of the ductwork is controlled in the fol-other step – now also rectangular ductwork has to meet lowing manner: The consultant points out which parttightness Class C. of the ductwork he wants controlled. REHVA Journal – January 2013 29
  • Articles The test fan (“provfläkt”) is connected to the ductwork where all openings are sealed (“täcklock”) (Figure 2). The fan is started and the airflow (“läckflöde”) needed to keep test pressure (“provtryck”) at e.g. 400 Pa is meas- ured. The actual leak factor is calculated by dividing the airflow (l/s) by the in situ measured (or taken from drawings) surrounding area of the tested duct system. The result is then compared with the leak factor for the prescribed tightness class as found in the AMA tables. Figure 3. An example of a duct connection fulfilling Class C requirements. The rubber seal is compressed and tightens the gap. tems that are easy to install. Both circular and rectangu- lar duct connections are provided with rubber gaskets that are very tight compared to older (and foreign) sys- tems. New types of duct joints have reduced earlier la- Figure 2. The test equipment for measuring the duct- borious installation works. work leakage from an article in 1966 by same author as this article – when AMA first required ductwork tight- Comparison of test results ness. The principle is still the same! in three EU countries The EU-project SAVE-DUCT found that duct systems in If this result is equal or lower than required the system Belgium and in France were typically 3 times leakier than is accepted. If not the contractor has to tighten the leak EUROVENT Class A, see Figure 4. Typical duct systems points and measure this part anew. He is now also re- in Sweden fulfilled the requirements for EUROVENT quired to check a new system part of the same size. (This Class B and C and were thus between 25 – 50 times is specified in AMA to be a 10% part of the system for tighter than those in Belgium and France. round duct systems and 20% for rectangular systems). If also this second measurement shows an unsatisfacto- ry result he has to check the whole system until every- 100 Occurrence, % thing is accepted. France 80 Belgium Is the testing worth the money? Sweden The costs for the tests – the first 10%, then next 10% if 60 not accepted and then the whole system - is part of the contract, i.e. covered by the contractor. 40 The mechanical contractor can either make the tight- 20 ness test with his own personnel, provided he has equip- ment and skilled personnel, or he can use a specialized 0 contractor. In both cases he has to cover the costs which 27*Class A 3*Class A 9*Class A can be quite considerable if the tests have to be repeated Class D Class C Class B Class A due to bad test results. More This has certainly led to high quality ductwork standard in Sweden for the following reasons. Figure 4. Results from the EU-project Airways. In the figure the bars show the percentage of tested The contractors do their best to avoid costly setbacks ductworks in each tightness class. The tightness class from inferior duct quality, the duct manufacturers are 3 x Class A etc. had to be expanded to fit the results competing in inventing and marketing tight duct sys- from leaky ductworks in the evaluation.30 REHVA Journal – January 2013
  • ArticlesFigure 5. The supply air duct for the flat is fixed to a light framework at the ceiling. The duct is hidden behind a clad-ding fixed to the same framework – everything is done, quickly, by the duct fitter.Why this large difference? The inhabitants of the house should be disturbed as lit-The most probable reason for this large difference is that tle as possible and for a very short time, preferably onlySweden has required tight ducts since the early sixties during one day. This is of course a new and interestingwhereas in the two other countries tightness of duct- market for the suppliers and several similar methods towork is normally neither required nor tested. solve this have been designed.Renovation of ventilation systems The illustrations show one of these systems where all theDuring the period 1965 – 1975 it was decided by the necessary components are prefabricated.Swedish Parliament that a large number of dwellingsshould be built to solve the acute crisis and reduce the Another example when an old ventilation installationhousing queue and improve the dwelling standard. was replaced can be found in a high-rise office buildingStatistics show that 1 006 000 dwellings (thus the name in downtown area of Stockholm.“The Million Program”) were built during this periodmostly in multi-family buildings but also to some ex- This building was the first of five rather identical high-tent in row houses. These houses have now reached an rise office buildings in the City Centre of Stockholmage when most of them are in acute need of renovation, (Figure 6). The architecture of the building was the re-not least when it comes to their installations. A stand- sult of an architectural competition (all five buildings,ard ventilation principle in those buildings was extract similar in height and dimensions, had its own archi-ventilation with air being supplied from the outside tect). They were the result of a drastic reconstructionthrough grilles in the external walls. of a large part of the downtown area of the city when most of the old 18th and 19th century buildings wereA common renovation solution today to improve the torn down and replaced with new office and commer-ventilation is to install a supply air system, keep – but cial buildings.clean and tightness test – the extract ducts and connectboth duct systems to a new air-handling unit installed The building was inaugurated in 1959, which wasin the attic space. This provides several important im- an extremely hot summer in Sweden. As typical forprovements: the air intake is thus placed high up toward the time, the window/wall ratio was high, 76%.the back side of the building instead of at low level to- Following the normal design in Sweden at that pe-ward the street, the supply air (even though it is much riod, the building was not equipped with any com-cleaner than in the previous case) passes through a high fort cooling.class filter (Class F7 is a common standard), a heat ex-changer reduces the energy use. The noise from the fans The supply and exhaust air was distributed through con-in the unit is attenuated to reduce the noise transmitted crete shafts connected on each floor to branch duct sys-through the ducts to the flats. tems. As there was no shadowing from other buildings the indoor temperature during the hot summer 1959To install a new supply air ductwork in an existing oc- raised to above 35°C and the top floors of the buildingcupied building requires new installation methods.. had to be abandoned for a few weeks. REHVA Journal – January 2013 31
  • Articles After nearly thirty years of operation the building was thoroughly renovated in 1997. All installations were re- furbished and the old ventilation system replaced with a modern air-conditioning system. New plant rooms were built on the roof of the building connecting to the old concrete shafts. Instead of using the shafts as plenums for supply and exhaust air respectively, the shafts were literally filled with circular ducts as each floor plan was provided with its own separate supply and extract ducts. As each floor represents its own fire cell, the supply and ex- haust ducts are provided with fire dampers (and regu- lating dampers) in the rooftop plant room as shown Figure 6. Ducts for the different floors pass down in Figure 6. through common shafts, one for supply and one for extract air. The photo shows part of the supply ducts This technical solution required that fifteen ducts were with their fire dampers. installed in each of the shafts. This was possible by us- ing circular ducts. The ducts were also delivered in 6- m lengths thus reducing the number of vertical joints Literature considerably. The very compact installation reduced the AIVC-TightVent workshop in Brussels, 28-29 March 2012. necessary space for the vertical shafts and increased thus AIVC-TightVent workshop in Copenhagen, 10 -11 October 2012. the floor area that could be let. ASHRAE. 2012. ASHRAE handbook—Fundamentals, Chapter 34 Duct Design. Atlanta: American Society of Heating, The design of the duct systems had to be studied in Refrigerating and Air-Conditioning Engineers, Inc. detail on how the supply and extract ducts were enter- Carrié FR, Andersson J, Wouters P. 1999. Improving ductwork. A ing to or emerging from the shafts to prevent unneces- time for tighter air distribution systems. AIVC, Air Infiltration sary collisions and facilitate the installation work. The and Ventilation Centre. ducts were tightness tested in turn as they were installed Malmstrom T, Andersson J, Carrié FR, Wouters P, Delmotte Ch. to prove that they were fulfilling the tightness require- 2002. AIRWAYS Source book on efficient air duct systems in ments of Class C. Europe. Belgian Building Research Institute. VVS AMA 98. Allmän material- och arbetsbeskrivning för VVS- Conclusion tekniska arbeten(General Material and Workmanship This Swedish way of working has been shown to be very Specifications of HVAC installations). AB Svensk Byggtjänst. effective in raising the quality of ductwork. Our long Stockholm 1998. Copyright 1998. (In Swedish). time focus on ductwork quality in Sweden has resulted VVS&Kyl AMA 07. Allmän material- och arbetsbeskrivning för in very low air leakage in normal Swedish duct installa- VVS-tekniska arbeten (General Material and Workmanship tions which has promoted air quality, thermal comfort Specifications of HVAC installations). AB Svensk Byggtjänst. and sustainability. Stockholm 2007. Copyright 2007. (In Swedish). REHVA Guidebook No. 17 “Design of energy efficient ventilation and air-conditioning systems” covers numerous system components of ventilation and air- conditioning systems and shows how they can be improved by applying the latest technology products. Special attention is paid to details, which are often overlooked in the daily design practice, resulting in poor performance of high quality products once they are installed in the building system.32 REHVA Journal – January 2013
  • Articles Ductwork airtightness requirements in PortugalPortugal introduced, for the first time, in the 2006 Building Regulations, a requirement on theairtightness of the ductwork in new HVAC installations. A test is required during commission-ing. Data on compliance is however still quite scarce to conclude how effective this require-ment is in practice. Eduardo Maldonado Fernando Brito Universidade do Porto, Portugal APIRAC ‑ Portuguese Association of HVAC Industries, PortugalEPBD context and CEN standards Commissioning requirements in PortugalThe EU Directive 2002/91/EC and its recast publishedin 2010 (Directive 2010/31/EU) on the Energy perform- As part of the transposition of the 2002 version of theance of Buildings (EPBD) only include requirements for EPBD, new regulations were adopted in Portugal andregular inspection of air-conditioning systems of an effec- came into force in 2006. Requirements for new HVACtive rated output of more than 12 kW (article 15), as well systems included for the first time a set of mandatoryas heating systems including a boiler with nominal power tests that must be carried out during commissioning,above 20 kW (article 14). Inspections should identify op- before the building receives its use permit.portunities for removing inefficiencies in the whole sys-tems in a cost-effective way. There is no specific require- Although there is no specific requirement on duct air-ment for ductwork air-tightness, but this is certainly one tightness for new HVAC systems in both versions of theissue that inspectors should analyse because leaking ducts EPBD, its relevance can be argued on the basis of thehave an important role in increasing energy consumption following arguments:in air-based heating and cooling systems. • The overall goal of the EPBD is to obtain energy-EN 15240 describes the methodology to perform in- efficient buildings. When a new building is com-spections for air conditionning systems. However, given pleted, all its components, both fabric and technicalthe large share of ventilation systems in the energy use systems, should be energy-efficient. Although thein buildings, CEN also developed EN 15239 for the in- Directive 2002/91/EC only required MS to put inspection of ventilation systems, even when they are not place minimum requirements for the building enve-included in the strict scope of article 15 of the EPBD. lope, the recast EPBD corrected that oversight andTogether with EN 15378, concerning the inspection of it now foresees minimum requirements for both en-heating systems, these standards cover the inspection of velope and technical systems components. It thusHVAC installations. seemed logical, even back in 2006, under the um- brella of the first EPBD, to impose a minimum per-Test procedures and measurement methods for air con- formance requirement on ductwork airtightness asditionning and ventilation installations are described part of the overall energy-efficiency requirements inin EN 12599. They include checks, for instance, of the the Portuguese building regulations.accessibility and cleanliness of the system according to • If a new ductwork system is not airtight from theEN 12097 and EN 15780, as well as measurements, start, it will be a lot more difficult and costly to makee.g., of airflow rates or ductwork leakage (with reference it airtight later, after an inspection report identifiesto EN 12237 and EN 1507). this opportunity for improvement. Recommenda- REHVA Journal – January 2013 33
  • Articles tions for improvements must be cost-effective and it had to be circulated and treated to compensate for the is often too costly to replace or to improve the perfor- leakage). Moreover, it was often impossible to meet the mance of an inneficient ductwork system. Therefore, minimum fresh air rates in many spaces, resulting in de- it also seemed logical that, in new buildings, duct- graded IAQ levels. The new regulation aims at ensuring work had to be airtight when it was first installed. minimum levels of IAQ and improved energy efficiency during operation of the building, by adopting a life-cy- Therefore, the 2006 Portuguese building regulations fo- cle perspective and moving away from the up-to-then cussed on ductwork airtightness for new systems being prevailing strategy of lowest possible first cost. installed, rather than just considering improving duct- work performance in the context of the regular inspec- To comply with the Portuguese regulation, ductwork tions required by the EPBD. leakage of air conditioning installations of buildings larg- er than 1000 m² may not exceed 1.5 l/s.m² under a static The aim of the tests is to demonstrate that the installa- pressure of 400 Pa (Class A limit according to EN 12237 tion is functioning as designed, in operational terms, but is 1.32 l/s.m² at 400 Pa). Air-tightness tests should be also meeting the minimum energy efficiency and indoor carried out using the following procedure (Figure 1): air quality (IAQ) targets set in the legislation. • A 10% random sample of the ductwork is Proof of the results of these tests, consisting of a detailed selected and tested by the inspector. If the report, must be handed to the Qualified Expert (QE) measured leakage is below 1.5 l/s.m², no further who will issue the Energy Performance Certificate (EPC) testing is required; for the building, who may ask for further tests if he/she is • If the first test is not satisfactory, a second test is not satisfied with the report or just for confirmation (ran- performed, after the contractor takes corrective dom check). Often, the QE is present while the commis- measures, again on the initially tested ducts sioning tests take place. The EPC is required by the local plus an additional randomly selected 20% of authorities before issuing the building’s use permit. the ductwork. If these tests are satisfactory, no further testing is required. Tests on the ventilation system include: • If the previous test is still unsuccessful, the contrac- tor must take additional corrective measures and • Airflow delivered to each room in accordance the final test(s) must cover the whole ductwork with design parameters; until the required airtightness is met. • Overall cleanliness of the whole ductwork and other components, such as air handling units and fans; This procedure was inspired by the AMA requirements • Airtightness of the ductwork. in Sweden. The regulations do not require a specific testing meth- The new regulations in action odology, but tests must follow recognised procedures, The new regulations apply to buildings larger than such as described in EN 12599. 1000 m² that begun their licensing procedure after 2006. Taking into account design and construction, this Ductwork airtightness test cycle usually takes, for large buildings, at least 3‑4 years Ductwork air-tightness is often considered to be an issue before completion. Therefore, there are not yet much in cold climates only. There has however been a signifi- data on the success of the new regulations. The first large cant amount of work in hot and mild climates, in par- buildings that had to comply with these new regulations ticular in the US, that demonstrates the important en- only finished the construction phase late in 2009 and ergy savings potential that can be achieved by reducing during 2010. New construction activity has also been duct leakage. quite low during the last few years due to the prevailing financial crisis and, therefore, the number of buildings In Portugal, up until 2006, there was no check on the affected by these new regulations is still rather small. quality of the ductwork (most often, building owners did not require the check simply to avoid its cost), and However, there is proof that the market adapted to the its performance was in general quite poor (high leak- regulations. The share of pre-fabricated round duct- age, cheap materials used), resulting in significant loss- work with quality seals between ductwork components es, with important negative consequences in terms of increased significantly (from <5% in 2006 to 30% in the energy efficiency of the whole installation (more air 2010). For rectangular ducts, the technology evolved to34 REHVA Journal – January 2013
  • Articles Requirements in technical prescriptions (class B, C, D, …) Airtightness control by ductwork installer Test of 10% of ductwork No Yes No OK? Improvements OK? System approved Test another 10% of ductwork No Yes No OK? Improvements OK? Test whole ductwork Yes No OK? ImprovementsFigure 1. Swedish approach in framework of AMA procedures. The procedure now in use in Portugal is identicalexcept for the initial requirement, which is defined in the regulation with a maximum leakage rate of 1.5 l/s.m² at400 Pa (Class A limit according to EN 12237 is 1.32 l/s.m² at 400 Pa). Conclusionachieve better seals along duct sections and at unions be-tween two consecutive sections, namely at the corners, It is too still early to say if the new regulations haverepresenting now 20% of the market (extraction ducts been successful (the number of completed new HVACcarrying air that is not recirculated, e.g., from toilets and installations falling under the new requirements is stillwet-zones, are still usually low-quality ducts). Welded rather small) and the data regarding the actual perform-and screwed joists disappeared since then. In parallel, a ance of few buildings constructed with the new require-few specialized companies now offer duct leakage testing ments have not been fully analysed yet for lack of sta-services in the market, while there were none in 2006. tistical significance. But ductwork technology evolved, and there is quantified proof that better quality com-Although only few EPCs have been issued for large new ponents are now much more used, and ductwork leak-non-residential buildings so far, there is anecdotal evidence age testing, as well as ductwork cleaning, are now newthat the required commissioning tests (not just ductwork niche markets that appeared since the new regulationsleakage) resulted, in most cases, in significant delays to the entered into phase, with the corresponding negative back-lash. Despite this, the new regulations that must be pub- Referenceslished to transpose the recast EPBD in Portugal, expected See the complete list of references of the article in thein 2013, are not expected to relax these air-tightness re- html-version at -> REHVA Europeanquirements for new ductwork to be installed. HVAC Journal REHVA Journal – January 2013 35
  • Articles The full length version of this article is available at the journal website Evaluation of air leakage and its influence on thermal demands of office buildings in Madrid Jordi Pascual Oscar Cámara Expert energy consultant Senior energy consultant Aleksandar Ivancic Damien Tavan Expert energy consultant Junior energy consultant All authors are from AIGUASOL, Barcelona, Spain Maria Casanova Development Senior energy consultant The methodology used is structured in two separate steps: firstly, the air leakage tests to determine the main parameters of the case study buildings. Secondly, mod- elling of infiltration allowing the characterisation of the Introduction transient model and the resulting data analysis. The major consequences of infiltration are the thermal losses derived from it, which account, in some instances, Air leakage test for high percentages of the total building’s thermal de- The different air leakage test standards consist in pres- mands [1] and therefore, in energy intensive buildings, surizing and de-pressurizing the study zone using ven- cause important economic losses. However, air leakage tilators (usually placing a BlowerDoor [2]) and deter- careful analysis and management is usually the excep- mining the necessary airflow to achieve a set pressure. tion rather than the norm. In the present case the tests were carried out in the four buildings at store level. Four office buildings in Madrid have been analysed at two different levels: air leakage tests and mathematical mod- This technique yields the Effective Leakage Area (ELA). elling. In this way real ELA, and the instantaneous and Assuming the total building’s air leakage through the mean infiltration values have been determined, as well as different cracks can be represented as the infiltration its effects on the heating and cooling demands. This proc- through a mouthpiece of equivalent area, the cracks’ ess highlighted different recurring building pathologies, dimensions can be represented as a single effective area which, although only tested in this small simple, lead to [3], or ELA. Thus, the ELA is usually used, at a set ref- belief this could be a clear picture of the current situation. erence pressure, to represent the leakage through the envelope. This analysis is a part of a bigger project on the multi- disciplinary study of the energy behaviour of commer- However, as some previous studies have shown [4], and cial buildings in Madrid, under the umbrella of the for a couple of the current analysed buildings, substan- major commercial district development “Desarrollo tial infiltration occurs between the study zones and some Urbanístico de Chamartín (DUCH)”. adjacent ones, some of which are unconditioned, con-36 REHVA Journal – January 2013
  • ArticlesTable  1. Characterisation of the analysed buildings. Parameter Units Description Building A Building B Building C Year year Year of building 2010 2008 2009 N_plan Storey Number of storeys 6 10 4 Type − Type of construction Heavy Light Light Per_window % Percentage of window > 90% > 90% > 90% Surf_bui m² Building’s total envelope 5 398 10 632 7 448 Vol_bui m³ Building’s total volume 25 147 93 600 36 689 Height_bui m Building height 23 42 15Table 2. Summary results of the air leakage tests. Building A Building B Building CELAtest (cm²) 7.479 5.483 1.295ELAZPD (cm²) 3.739 0 0ELA (cm²) 3.739 5.483 1.295ELA (cm²/m² facade) 6.36 17.69 4.56Roof and slab infiltration ratio over the total (R) 0.23 0.02 0.04sequence of a deficient building process. Thus, it be- influence of the pathologies in the building envelopecomes necessary to differentiate between external and and the ones in the internal partitions adjacent to un-internal air leakage. To achieve this, the Zone Pressure conditioned spaces posed too high an obstacle for theDiagnostic (ZPD) was used, which indicates what the consecution of reliable results.corresponding ELA is for the analysis zone with regardsto the adjacent and non-external surfaces, and so the The characterisation of the three analysed buildings isELA for the external ones [5]. determined through the parameters on Table 1.Infiltration modelling Out of the field test undertaken for the three buildings,Infiltration can be broken down into a climate inde- Table 2 shows their characteristic values.pendent component (ELA), and another dependent onclimate conditions, in a non-lineal effect. The climate It can be observed that the infiltration levels betweenindependent component can be partially quantified by floors are only relevant in Building A, and that the ELAthe field tests, whilst the climate interaction requires of a of building B is greater than for the other two buildings.model to calculate its effect. The ASHRAE’s [6] recom- These parameters are the ones used in the equations ofmended Lawrence Berkeley Laboratory (LBL) have been the LBL methodology implemented.used for this purpose. This model establishes that air in-filtrations are a function of permeability of the building The shown results, although being one of the objec-and the pressure differences through its envelope. These tives of the analysis, are not very intuitive. In order topressure differences are induced by air temperature dif- make them clearer, they are applied to the different con-ferences (Stack effect) and the wind’s pressure. ditions and TRNSYS [7] models for the buildings, so that the air renovations due to infiltration and their ef-The above-described methodology has been implement- fect on the buildings’ thermal demands can be obtained.ed in TRNSYS, considering weather and monitored da- As an example, the infiltration instantaneous values forta, with the aim of achieving transitory infiltration val- the same week in April are shown for the three build-ues, and the determination of the effect of air leakage in ings (Figure 1).the buildings’ thermal behaviour. The results were synthesized into a weighted averageResults and discussion value for infiltration (average infiltration values for theThe exposed methodology has only been implemented considered time interval, based on wind speed ratios forin three of the four buildings originally selected. In the each orientation), a variation in demands and powerremaining one, although the air leakage test was tried, on the Spanish regulatory reference (variation of ther-the required pressure differential values (50 Pa) were not mal demands with calculated instantaneous infiltrationachieved due to the construction pathologies. Both the vs. infiltration derived from the interpretation of the REHVA Journal – January 2013 37
  • Articles Spanish regulation [4-8]), and variation in demands and power supposing no infiltration (variation of thermal demands with cal- culated instantaneous in- filtration vs. no infiltra- tion). Table 3 shows values obtained using monitored climate data from February to September. Where the variations on demands are obtained by comparing the excess (pos- Figure 1. Instantaneous values of infiltration in the three buildings, for a week in April. itive) or the default (nega- tive) of the integrated temporal values of the reference through the comparisons with no infiltration scenarios. The case over the entire period, versus the integrated tempo- major influence on heating demands vs. cooling ones could ral values of the real case over the entire period. By fol- be due to a combination of the high internal loads of these lowing the same procedure, positive values for Power buildings, and because of minor infiltrations in summer sea- means that reference case have a bigger value, while nega- son when, at the same time, non-occupancy periods exists. tive one’s means the opposite. The variables whose values are 100, indicate that in the reference case, the values of It is worth mentioning, based on the established values demand or power are zero. and the singularities observed during the field tests, that, mainly in the A and B buildings, the result is a reflection In the data can be observed the proportion of the weight- of a poor quality in the construction process, rather than ed infiltrations and, most importantly, the great variation not meeting the current regulatory standards. Equally, in demands and powers between the models based on real comparing the results obtained with other references for data and those based on regulations. Also the weight of the office buildings in the US [1] or Australia [9], the mag- infiltration on energy demands and powers can be noticed nitude order is very similar. Table 3. Summary of transitory results of the infiltration models. Parameter Units Description Building A Building B Building C  1/h Weighted average infiltration value 0,44 0,81 0,27 Q f _ ave Cooling demand variation percentage on ΔQCSPAREG % Spanish regulation reference 1 14 1 Heating demand variation percentage on ΔQHSPAREG % Spanish regulation reference −79 −100 −78 Cooling power variation percentage on PCSPAREG % Spanish regulation reference −4 −11 −4 Heating power variation percentage on PHSPAREG % Spanish regulation reference −72 −100 −83 Cooling demand variation percentage on no ΔQCNOINFIL % infiltration 3 17 3 Heating demand variation percentage on no ΔQHNOINFIL % infiltration −94 −100 −91 Cooling power variation percentage on no PCNOINFIL % infiltration −6 −13 −6 Heating power variation percentage on no PHNOINFIL % infiltration −100 −100 −10038 REHVA Journal – January 2013
  • ArticlesHowever, it is very compli- Table 4. Infiltrations for the comparative analysis between buildings and on keycate to compare the results parameters.for the three different build- Infiltrations Building A Building B Building Cings, as those have very dif- Base Results 1/h 0.44 0.81 0.27ferent characteristic parame- Normalization by height 1/h 0.44 0.62 0.32ters. That is why the results Normalization by form factor 1/h 0.44 1.18 0.34were normalised based on the Normalization by ELA 1/h 0.44 0.56 0.77buildings’ height (parameteraffecting the wind speed di-rectly), the ELA (air tight-ness level for the façade),and the form factor for thebuilding (ratio envelope sur-face/volume). Normalizingeach of these parameters forBuilding A the following areobtained:Figure 2 is a graphic repre-sentation, hourly based andfor a week in April, of the val-ues in Table 4.It is seen that the ELA is themain factor in the models.The second one is the heightwhich conditions the windon the façades. The form fac-tor appears as a second orderderivative influenced for theother two parameters.ConclusionsThe main conclusions referto the feasibility, necessityand interest in undertakingthis type of test, both in newconstruction and in existingbuildings. It is also necessaryto integrate detailed modelsin the design tools, verifica-tion and buildings’ intelli-gent energy management, aswell as in certification tools.Implementing such analysisin the building process woulddetect building pathologies,enabling the improvementof the construction processesby establishing priorities de-pending on the constructivesolutions adopted. It would Figure 2. Infiltrations, for a week in April, of the three buildings considering B and Calso allow the design process normalised to A-building’s height (top), ELA (centre), and form factor (bottom). REHVA Journal – January 2013 39
  • Articles to be informed under cost-efficiency parameters, clos- er to reality certifications, as well as a more accurate intelligent building management. Equally, and taking into account other similar projects undertaken in dif- ferent latitudes [10], a more deep analysis and from a stronger architectural point of view could relate con- structive pathologies and architectural solutions, with different values for the present latitudes. For the analysed buildings, their infiltration values are considerably high, with the consequent effect on the thermal demands and high-energy bills. This is mainly due to a poor construction process and prac- tice, although having small form factors, or being low buildings, helps minimizing such effect. Equally, the order of magnitude in the variation of demands with respect to the normative case would justify, in terms of running costs, undertaking the necessary re- forms to fix these problems. The strongest evidence lies in the building where the test could not be suc- cessfully completed due to the elevated air leakage both with the outside and the adjacent spaces. One should question if this is just an exception or the norm in old enough buildings (1992) in this geo- graphical location. References [1] Impact of Infiltration on Heating and Cooling Loads in U.S. Office Buildings. S. J. Emmerich, et Al. US. Department of Energy, Office of Building Technologies. Agreement No. DE-AI01-01EE27615. [2] [3] M.H. Sherman, “Estimation of Infiltration from Leakage and Climate Indicators”, Lawrence Berkeley Laboratory, University of California, Berkeley (1980). [4] Gong, X., Claridge, D.E., Archer, D.H. 2010. Infiltration Investigation of a Radiantly Heated and Cooled Office. ASHRAE Transactions, Vol 116, Part 1. [5] “Zone Pressure Diagnostics (ZPD) Calculation Utility, Software User’s Guide”. The Energy Conservatory, Minneapolis (2004). [6] “Handbook of Fundamentals, Chapter 25: Ventilation and Infiltration”, ASHRAE (1997). [7] TRNSYS, Transient System Simulation Tool. © University of Wisconsin 2012. [8] Código Técnico de la Edificación (CTE) HE 2.3, y Condiciones de aceptación de procedimientos alternativos. Instituto para la Diversificación y Ahorro Energético (IDAE), Ministerio de Indústria, Turismo y Comercio 2007. [9] Air tightness of australian offices buildings: reality versus typical assumptions used in energy performance simulation. A. M. Egan. Australian National University. Proceedings of Building Simulation 2011, P_1133. Zone sealing for airtigthness testing (two first [10] Methods and techniques for airtight buildings. F.R. Carrié, ones) and bottom one BlowerDoor installation R. Jobert, V. Leprince. AIVC - Document -CR14. © CETE de for tightness testing Lyon40 REHVA Journal – January 2013
  • Articles Energy efficiency strategy at the portfolio of a property owner Yona Kamelgarn Frank Hovorka Sustainable Real Estate Researcher Director Sustainable Real Estate Novethic, France Caisse des Dépôts et Consignations, France frank.hovorka@caissedesdepots.frProperty owners are moving from implementing energy efficiency on pilot projects toimproving energy efficiency on their whole portfolio. Such was the conclusion on the ThirdSustainable Investment Conference held in Expo Real 2012 where different investors andinvestment managers introduced their strategy. French public investor Caisse des Dépôtset Consignations (CDC) was one of them.A t the end of 2009, CDC initiated the GRECO compared to thermal calculations so as to determine a project with its asset manager AEW Europe, breakdown of energy consumption per use (heating, to anticipate the French environmental law cooling, lighting, ventilation, DHW, lighting, others).“Grenelle 2”. In accordance with the EPBD directive, Recommendations were then issued to improve energythe Grenelle 2 stipulates a regulatory obligation to re- efficiency for each energy use. The resulting actions wereduce by 38% the energy consumption of existing com- stored in the platform, so that they could be combinedmercial property stock by 2020. Although this law had into different scenario by the asset manager. The result-not been formally enacted by an implementing decree, ing refurbishment scenarios were assessed both accord-CDC was willing to promptly address the issue so as to ing to energy efficiency and to cost effectiveness, as pre-limit the depreciation risk for its existing portfolio since sented in Figure 1.refurbishment works would likely need to be undertak-en, and to spread the refurbishment cost over time. In A dynamic internet platform was thus developed to:order to benefit from a broader view, this project wasapplied to both residential and commercial properties. • Store the collected data: The platform provides aA dynamic tool was built to store financial, environmen- space to store simultaneously financial, technicaltal and technical data, help investment decision-making and environmental data.and monitor the implementation of the action plans. • Help investment decision-making: The platform allows the asset manager to analyse the financialMethodology and environmental impacts of differentThe project was first applied to assets in direct man- refurbishment scenarios. The possible energyagement and ownership. This portfolio represents one efficiency measures recommended by the thermalfourth of the total CDC’s exposure to real estate. It con- engineers on each asset are stored in a database.sists in approximately 250 000 m², two thirds of which The asset manager can combine these actions tocorrespond to residential properties. build refurbishment scenarios and assess their impact on the overall portfolio performance.The impacts of future regulatory requirements on this He can also monitor the impact of buy and saleexisting portfolio were assessed through the analysis of decisions.the refurbishment work required to comply with the • Monitor the implementation of the action38% objective either globally or asset by asset. First, plan: the tool is designed to monitor both theenergy audits were carried out on the whole portfolio. estimated consumption from the energy auditsActual consumption invoices (tenants and owner) were and the actual consumption. REHVA Journal – January 2013 41
  • Articles Figure 1. Underlying principles of the GRECO Project (Greco project). 600 Primary energy consumption 500 400 (kWhp /m²/an) 300 200 100 0 before 1930 1930 1950 1950 1970 1970 1980 1980 1990 after 1990 Figure 2. Average primary energy consumption per construction period. Results from the energy audits The platform is designed to gather information on the different assets along the buildings ‘hold period. This The energy audits aimed to assess intrinsic building con- includes building plans, maintenance and operation ex- sumption. They included all energy consumption for heat- penses, energy and water consumptions from tenants’ ing, air conditioning and ventilation. Only plug loads for invoices… For new acquisitions, the platform should be common areas were accounted for. Common hypothesis able to store information from due diligence. Ultimately, were used for occupancy, air change rate and temperature this should provide the asset manager with an extensive set-points. The results pointed out a relative homogeneity “building passport” for all assets, with technical, finan- between buildings from the same period of construction cial and environmental indicators. (Figure 2). As shown in previous studies [1], the assets42 REHVA Journal – January 2013
  • Articles 6 Energy consumption abatement cost (€ / kWhf saved) 5 4 3 2 1 0 before 1930 1930 1950 1950 1970 1970 1980 1980 1990 after 1990Figure 3. Average final energy consumption abatement cost per construction period. 60 Final ernergy consumption 50 reduction target (%) 40 30 20 10 0 before 1930 1930 1950 1950 1970 1970 1980 1980 1990 after 1990Figure 4. Final energy consumption reduction target per construction period.built during the seventies have the highest energy con- These results are consistent with life cycle considerationssumption. Yet, this structure differs when analysing the and building obsolescence [3]. On average, heavy refur-cost of the energy saved thanks to the refurbishment work bishment works and equipment replacements occur af-(cost efficiency of the refurbishment) (Figure 3) and the ter a timeframe of twenty to thirty years. Buildings fromenergy consumption reduction target that can be achieved the last construction period will not be due for those re-at a reasonable cost (Figure 4). furbishment works until after 2020. It would not be cost efficient to refurbish them sooner, other than throughAlthough they present the highest energy consumption, regulation and lighting optimisation, which would notthe properties from the seventies are among the easiest concern the building structure or the HVAC refurbish. For this building group, it appears possi-ble to reduce energy consumption by 48% for a cost Since residential properties do not yet present a legalefficiency of approximately 1.8€ per kWhf saved [2]. obligation to refurbish, it was chosen to set a reductionConversely, the more recent buildings require impor- target by 2030 for recent residential buildings rathertant investment to reach only low energy consumption than by 2020. Nearly all the refurbishment works rec-abatement. ommended are feasible in occupied sites. REHVA Journal – January 2013 43
  • Articles Table 1. Greco Project - Main indicators. Portfolio Time Refurbish­ment Cost efficiency Refurbishment cost Primary energy frame costs (€/m²) (€/kWhf ) to asset value (%) reduction target (%) Commercial 2020 173 1.34 4.0% 39% Residential 1 2020 100 1.07 2.1% 36% Residential 2 2030 288 3.06 4.1% 32% Ratios for decision-making the asset market is likely to be concerned with a demand The first stage of this project has highlighted several in- for greener buildings. dicators that were examined simultaneously for refur- bishment decision-making. Main figures are presented Impact on value - a case study in Table 1. The impact of environmental upgrades on value was il- lustrated through a heavy refurbishment project which Refurbishment cost was undertaken at the beginning of 2010. This project The total refurbishment cost linked to energy efficiency was used as a case study to explore the links between en- upgrades appeared as mostly covered by the traditional ergy upgrades and their impacts on asset value. Since the budgets for major repairs and maintenance. This cor- building is now completely commercialised, it was pos- responds to the fact that major upgrades were timed to sible to compare predictions with effective data. coincide with the replacement of components at the end of their life. The additional cost is difficult to assess and Background issues results mainly from the choice for more efficient instal- Savings on energy expenses only cover a small part of lations. At a building level, the refurbishment cost and the investment required by the refurbishment. Does this resulting payback periods were not the only criterion mean that energy upgrades are not worth it for the in- used for decision-making since they do not inform on vestors? Different studies have shown that the benefits cost efficiency or impacts on assets value. offered by sustainable buildings amount to more than energy and water savings. In office buildings, sustaina- Cost efficiency ble features improve occupants ‘comfort therefore boost- Comparing the refurbishment cost and the energy con- ing the employees’ productivity. Academic studies have sumption abatement target informs on the cost efficien- proven that these benefits are already reflected in the cy of the refurbishment scenario. It appears as the most market with approximately a 10% premium in market suitable indicator to decide between different actions to values, a 6% premium in rental values and an increased meet the reduction target. The energy audits (Figure 4) liquidity in transactions (Table 2). Although one can highlighted discrepancies between assets with cost effi- wonder whether this premium will last or whether it ciency ranging from less than 1 to more than 8 euros per will evolve into a discount for buildings with poor envi- kWhf for reduction targets between 30 to 40%. ronmental performance, environmental features can no longer be ignored in refurbishment decision-making. Refurbishment cost to asset value ratio When accounting only for energy expenses, the invest- Data ment payback period exceeds 8 years. Yet savings in en- Franklin building is an office building of 7500 m², built ergy expenses are not the only benefit from energy up- in the 1930´s and located in Paris Central Business grades. The impact on the asset value should also be District. In the beginning of 2010, as two of the main considered. The comparison between refurbishment leases came to an end resulting in a two-thirds vacant cost and asset value was used to indirectly assess the building, a heavy refurbishment was decided. The risks linked to the regulatory obsolescence generated by project aims the HQE certification and the BBC [4] “Grenelle 2”. This ratio will depend on the functional refurbishment energy label. It should be delivered by the quality of the asset and its location. Even with long pay- end of 2012. The building is already completely com- back periods, it may be more beneficial to refurbish if mercialised with above average rental prices.44 REHVA Journal – January 2013
  • ArticlesTable 2. Main results from academic studies on “green value” for office buildings. Market Rental Occupation References Certifications value value rate Fuerst and McAllister LEED, Energy Star (USA) 31-35% 6%   (2008) LEED (USA)   15-17% 16%-18% Wiley et al. (2008) Energy Star (USA)   7%-9% 10%-11% LEED (USA) 10%     Miller et al. (2008) Energy Star (USA) 6%     Kok (2008) LEED, Energy Star (USA) 16% 6%   Energy Star (USA) zones under Pivo and Fisher (2009) 6.7%-10.6% 4.8%-5.2% 0.2-1.3% redevelopment Fuerst and McAllister LEED (USA)     8% (2010) Energy Star (USA)     3% LEED (USA) 11% 6%   Eichholtz al. (2010) Energy Star (USA) 13% 7%   Chegut et al.(2011) BREEAM (Londres, GB) 26% 21%   Kok, Newell and NABERS 5 stars (Australia) 9% 3%   MacFarlane (2011) Green Star (Australia) 12% 5%   Fuerst and McAllister Energy Star, LEED (USA) 25%-26% 4%-5%   (2011)In order to assess the added value from the environmen- Resultstal retrofit, different scenarios were considered: The main results are presented in Table 3. • Business As Usual (BAU): No refurbishment Table 3. Main results from the Franklin case study. is implemented. Only standards maintenance operations are performed. The rental prices used   BAU RT HQE correspond to rental prices for second hand Investment (€) 0 13 000 000 18 300 000 buildings. The asset liquidity is deemed as poor Annual rental revenue 4 288 611 5 685 730 6 054 200 thus leading to higher exit yield and higher (full occupancy) (€) vacancy. Annual Rental 1.50% 1.60% 1.70% • Conventional Refurbishment (RT): As regards growth rate (%) energy efficiency, the refurbishment does not Discount rate (%) 7.75% 6.80% 6.70% go beyond the current regulatory requirements. Vacancy period The asset is valued as first-hand building but between leases 12 10 9 does not benefit from a green premium (average (months) rental price in the first-hand market). The asset Maintenance and liquidity is deemed to decrease over time. operation costs 124 257 91 855 76 310 (including vacancy) (€) • Green Refurbishment (HQE): This is the actual situation. The energy upgrade enables the owner DCF t=0 calculation (accounting for 52 748 917 82 191 774 88 243 576 to benefit from a green premium in rental prices investment costs) (€) and very good liquidity in the market. Asset value t=1(€) 52 748 917 89 926 650 100 377 224The valuation was performed using a discounted cashflow method. To assess for the difference in values due For Franklin building, the discounted cash flow calcu-to the absence of environmental features, longer va- lation (Figure 5) shows that the two refurbishment sce-cancy periods in between leases were used in addition narios (RT and HQE) lead to lower cash flows respec-to the differences in rental and exit values mentioned tively until years 7 and 9. Yet, over the long run, theypreviously. present the highest NPV. REHVA Journal – January 2013 45
  • Articles 50 000 000 40 000 000 30 000 000 cashflows ( €) BAU 20 000 000 RT 10 000 000 HQE 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 10 000 000 years 20 000 000 Figure 5. Evolution of the cumulated discounted cash flows over time. However, as regards value, a refurbishment appears fi- The main benefit from green refurbishment lies in its nancially beneficial from the start since it enables the impact on long term value. Whether on a pessimistic owner to increase its rental revenue and decrease fu- (depreciation of poor performing building) or on an ture depreciation risks. The initial investment costs are optimistic scenario (premiums for the environmental- offsets by the future benefits, in particular due to the friendly building), green retrofit should not be only an- higher exit rate that can be expected. HQE refurbish- alysed through conventional paybacks period but con- ment which investment costs represent approximately siderations on their impact on the possible evolutions a third of the initial building value enabled the inves- of assets value should be accounted for. Value distribu- tor to nearly double the initial value of its asset. In ad- tions instead of a single expected value can also be used dition, it leads to a 10% value premium compared to to inform on risks and uncertainties. RT refurbishment. These results highlight that tradi- tional payback calculations accounting only for energy Sources savings are misleading. They do not account for the Chegut , A., Eichholtz,P., Kok, N. (2011) The Value of Green Buildings: main benefit of green refurbishment which appears in New Evidence from the United Kingdom. European Centre the long run. for Corporate Engagement. Available on ECCE website. ORIE (2012) Obsolescence et Grenelle 2. Report from the Conclusion “Obsolescence and Grenelle 2” Working group. Sayce, S. Sundberg, A, Clements, B. (2010) Is sustainability reflect- As energy retrofits become a regulatory requirement, in- ed in commercial property prices: an analysis of the evidence vestors will require energy efficiency strategy at a portfo- base. RICS Research Report. lio scale. Decisions will not only concern choosing refur- Reed, R. Warren-Myers, G. (2010) Is sustainability the 4th form of bishment scenarios within buildings according to tech- obsolescence? PRRES conference 01/2010. nical criteria, but will also require prioritising between assets to maximise the value of the portfolio over time References according to financial and environmental criteria. [1] In particular, results obtained are consistent with Sinteo Barometer on energy consumption (an annual French Barometer on energy consumption and refurbishment costs). Greco project was designed to meet these stakes. The [2] Electricity price in France ranges between 8c€/kWh and first phase of this project has already been implemented 12.6c€/kWh. with the design of a platform to store assets character- [3] In its 2012 report on the impact of “Grenelle 2” on building istics and possible refurbishment works. The data col- obsolescence, the research center on commercial real es- lection was a crucial step for this phase since data were tate in Paris region, ORIE, assessed the investment required scattered among the different actors. The main conclu- to achieve Grenelle 2 targets by considering building refur- sion from the refurbishment recommendations high- bishment cycles. It showed that the target was reasonably achievable if refurbishment work were implemented accord- lighted that energy upgrades will not require an addi- ing to the building maintenance cycle and if energy con- tional budget but will mainly be supported through a sumption was optimised through regulation. reallocation of the existing major repairs and mainte- [4] BBC label corresponds to an intrinsic primary consumption nance budget. of 80kWh/m².year.46 REHVA Journal – January 2013
  • Articles A new innovative Ground Heat Exchanger for heating, cooling and energy storage John Ljungqvist, Thomas Vogel and Lars Nielsen All authors are from Corporation. Contact email: Lars.Nielsen@uponor.comUponor has developed a new innovate ground heat exchanger in conjunction with theMESSIB project co-financed by the European Commission under the Seventh FrameworkProgramme (FP7).T he overall objective of MESSIB project is the de- tion of the energy demand and the decrease of thermal velopment, evaluation and demonstration of an gradients and temperature variations. affordable multi-source energy storage system(MESS) integrated in building, based on new materials, The Uponor development TIL-GHEXtechnologies and control systems, for significant reduc- The Uponor development under MESSIB is a so-calledtion of its energy consumption and active management TIL-GHEX (Thermal Insulated Leg – Ground Heatof the building energy demand. Exchanger). It consists of a central thermally insulated pipe (40 mm) and a number of (between 6 and 12) out-Among the innovative elements in MESSIB is Advance er active pipes (16 mm) acting as heat exchangers con-ground storage (GS) technology combined with radiant nected through a manifold at the bottom and at the topsystems and ground thermal contact improvement by the of the borehole.development of a conductive fluid material (CFM). Thebasic idea behind energy storage in buildings is to provide The high number and small diameter of the outer pipesa buffer to balance fluctuations in supply and demand. will increase the efficiency of the heat exchange and hence increase the thermal performance simply becauseThe need for energy storage the surface area between the collector and the surround-One of the challenges of today’s energy systems is to way ing ground is higher. Using a laminar flow the pressureto match the demand and the supply. Reliable storage drop in the outer small dimensioned pipes is minimizedsystems for short as well as long term are hence essen- and there is no increased pressure drop over the circu-tial for efficient energy systems and further integration lation pump compared to the larger pipe dimensionof renewable sources. in traditional collectors. Since the Uponor TIL-GHEX ground energy collector is able to maintain a low bore-State of the art storage technologies for thermal energy hole thermal resistance even at low flow rates, one caninclude: Underground thermal energy storage (UTES), also take advantage of utilizing variable speed pumpswater tanks above ground, rock filled storage with air and hence save energy without a negative influence oncirculation, phase change materials (PCM) and ther- the heat transfer coefficient. The idea behind the ther-mo-chemical storage. The scope of the MESSIB devel- mally insulated central pipe is also to be able to keep aopment on thermal storage is to increase of the energy high temperature drop over the heat exchanger which isefficiency and indoor comfort in buildings by the reduc- beneficial for cooling purposes. REHVA Journal – January 2013 47
  • Articles Design principle of the TIL-GHEX compared with a traditional U-collector design. Comparison with traditional U-pipe TIL-GHEX benefits storage and collectors The TIL-GHEX allows a higher energy transfer between The efficiency of a ground energy borehole is influ- the ground and the collector to a low borehole thermal enced by two factors. Firstly, the temperature difference resistance. This means that the depth of the borehole between the inlet and the outlet flow of the collector. by up to 50% with the same thermal output. While the Secondly, the heat transfer coefficient between the col- TIL-GHEX collector is more costly than a conventional lector and the surrounding ground which is normally collector, the total costs of installation are lower due to referred to as the inverted value of the thermal heat re- the reduced borehole depth. sistance. The second factor is also influenced by the to- tal surface area between the collector and the surround- The TIL-GHEX collector displays a high thermal re- ing ground. Two main parameters influence the thermal sistance between the downward and upward going flow heat resistance: The thermal resistance between the up- regardless of the flow rate. In contrast, the performance ward and the downward going flow (Ra) and the bore- of conventional collectors depends on the flow velocity, hole thermal resistance (Rb). with high losses at a low flow rate and clearly inferior performance even at high flow rates. One of the drawbacks with conventional collectors is that there is an undesired heat transfer between the up- In summary the Uponor TIL-GHEX collector extracts ward and downward going flow. The thermal resistance a maximum of thermal energy which is transported up between the upward and downward going flow is most- to the ground surface by a number of low diameter out- ly denoted Ra and should be as high as possible. With er pipes (between 6 and 12). This applies to the heat- Uponor TIL-GHEX ground energy collectors that un- ing mode. For cooling the direction of transportation desired heat transfer is minimized through the insu- is the opposite. lated central pipe causing a higher Ra. The other draw- back with conventional collectors is that the desired Thermal Response Test (TRT) heat transfer to and from the surrounding ground is low A thermal response test (TRT) is a procedure that is car- compared to what can be obtained from a physical point ried out in order to measure the heat transfer performance of view. To obtain a high heat transfer between the fluid between the fluid in the GHEX (Ground Heat Exchanger) in the pipes and to the surrounding ground, the bore- and the ground. The TRT is performed to make a cost ef- hole thermal resistance denoted Rb has to be low. fective BTES (Borehole Thermal Energy System) design.48 REHVA Journal – January 2013
  • ArticlesThe heat transfer performance can be divided in thethermal performance in the ground and the ther-mal performance in the borehole. Whereas it is dif-ficult to influence ground thermal conductivity it ison the other hand easy to influence the thermal per-formance for the borehole by the GHEX (GroundHeat Exchangers) design and the material in theborehole.Typical heat transfer rates in a GSHP (Ground SourceHeat Pump) installation differ from 30−50 W/m, buthigher rates as 100 W/m can be realized if solar collec-tors are used to charge the bore hole with heat that isgoing to be seasonal stored in the ground.As part of the MESSIB project, a Thermal ResponseTest has been performed on two prototypes and themeasured Rb values compared with a single anddouble U-loop for different brine flows. The resultshave proven that the TIL-GHEX offers consider-ably lower Rb than single and double U-loop. TheTIL-GHEX has shown borehole thermal resistancearound 0.02 K/Wm (dependant on the flow rate)while traditional U-collectors show thermal resistancein the range of 0.04 K/Wm (turbulent flow) and upto 0.07 K/Wm (laminar flow). The TIL-GHEX per-forms in particular better at laminar flow rates. Thereason to that is that U-loops with large hydraulic di-ameters have to operate in turbulent flow regime toperform optimally.Demonstration ProjectsThe MESSIB project demonstrates concept and solu- Uponor TIL-GHEX.tion of the project at three locations; one is a single-family like house in Greece. The other demonstratorswhich monitor the performance of the Uponor GHEXas a part of embedded system are located in Freiburg/Germany and Paterna/Spain. storage technology plays a vital role for balancing the fluctuations in supply and demand. Reliable storageFurthermore, the TIL-GHEX has currently been in- systems for short as well as long term are hence essen-stalled at a number of demonstration projects through- tial for efficient energy systems that contribute posi-out Europe, including Freiburg in Germany, Virsbo in tively to a sustainable construction development.Sweden and the new office building project Plaza Loistein Vantaa, Helsinki, Finland. The performance of the Being part of the MESSIB project has allowed Uponorinstallations will be monitored for future improvement to develop a co-axial TIL-GHEX ground collectorand optimization of the TIL-GEX and its interface to and store system with proven superior thermal per-the integral building energy system. formance. The developed products and systems are already being installed within commercial projectsConclusion and Perspectives which form a good basis for further improvementsSustainable heating and cooling technologies for and commercialisation of efficient ground energy stor-buildings is key to reduce the overall energy consump- age systems.tion in the construction sector and further integraterenewable energy sources. Improved thermal energy For further information please visit REHVA Journal – January 2013 49
  • Articles Improved energy efficiency of air cooled chillers In these last 10 years awareness in energy saving has continuously increased in both industrial and HVAC applications, we strive to regulate the electrical consumption of cooling equipment using the most effective efficient techniques. In the refrigeration and heat pump sectors in- creasingly European standard and directives are now applied to the appropriate and proper use of materials, innovation and in the application of new technologies to improve refrigera- tion system efficiencies. HVAC designs for Data Centre Maurizio Burba – Total Load 2.6 MW Hitema Managing Director In the refrigeration and air conditioning sector continu- ous attempts are made to reduce the energy consump- tion of all systems by improving the management of cooling power, optimizing the use of water-glycol flow and providing greater temperature accuracy. Recent re- equivalent electrical capacity is lower. Moreover the search has developed the use of environmentally friend- compactness and longevity of inverters above film ca- ly refrigerants with lower ambient impact and excellent pacitors is also a consequence of superior effectiveness thermal performances. However, large refrigerant equip- of cooling directly with liquid refrigerant line. When the ment still has very high power requirements, especial- frequency increases the number of compressor revolu- ly those demanded from very large air or water cooled tion increases linearly. As frequency increases compres- chillers with screw compressors. The utilization of screw sors r.p.m. increases and as frequency decreases compres- compressors is very high amongst large capacity chill- sor r.p.m decreases. The application frequency range was ers (>300 kW) and therefore the optimization of par- widened between 30 Hz to 130 Hz. tial load performance, which is a condition present in almost all refrigeration plants at various stages through- Main advantages are: out the year, is the goal prefixed by Hitema. A modern and intelligent technology is to control the large power • The starting current is effectively equal to 0, as demands of screw compressors with the frequency con- current is directly proportional to frequency, the trol network, using inverter electronic devices. inverter starts the screw compressor with void frequency and it causes an absorption equal to 0. Advantages offered with • Cooling power can increase up to 20% above the the Inverter Technology optimal cooling power referred at 50 Hz, this is be- An inverter (VDF) is an electrical device acting on the cause the screw compressor can rotate with higher variation of voltage and frequency. The inverter uses gears reaching higher frequencies up to 130 Hz. the line alternate voltage (a.c.) to produce a direct volt- • Higher operating flexibility due to large range of age (Diode Bridge - d.c.). From this direct voltage an control (from 16% to 100%, widest modulation alternate voltage is regenerated (PWM technique) with range on the market) and higher power density. a frequency f between 0 and fmax (maximum frequency) • Reduced electrical consumption at partial and voltage V<Vnet (electric net voltage). load between 30 Hz and 50 Hz compared to a standard screw compressor with a slide valve Inverters are widely used in film-polyester capacitor capacity control. This results in a measured configuration, which is similar technique used on pho- absorbed power being reduced by up to 15%. tovoltaic plants. The absence of electrolytic materials • Superior control of water outlet temperature avoids the early aging due to the temperature, currents exhibiting less fluctuation around the set point and stocking periods. The current distortion THDI temperature. Typically tolerances of around is much lower than is electrolytic capacitors since the +/- 0.5°C are possible.50 REHVA Journal – January 2013
  • Articles • Reduced mechanical compressors wear, as the Compressor absorbed power chiller and the total power consumption of the refriger- screw will rotate for most of year with reduced ation unit (compressors + fans). If the cooling load de- 65 r.p.m. (higher MTBF). creases whilst the ambient temperature decreases, then • Inverter technology with screw compressor the absorbed power of chiller decreases much more rap- 55 variable Vi, using automatic control of Vi the idly than the reduction in cooling capacity in a non-lin- performances of chiller increase. ear relationship. Power [kW] 45 Performance of a Hitema chiller with These COP and EER values are very competitive with compressorsCompressor absorbed power driven by inverter other available technologies (eg, centrifugal compres- 35 sors) and COP values with inverter screw compressors 65 25 Compressor absorbed power can attain >8 and EER >7. This chart above refers to an 55 40 50 60 70 80 90 air cooled chiller with R-134A refrigerant, with inlet wa- 100 110 Power [kW] ter temperature of 12°C and outlet water temperature 45 Load [%] of 7°C. The graph illustrates the massively beneficial ef- 35 with slide valve with inverter fect on the efficiency of the chiller unit as the ambient 25 air temperature and the load on the chiller reduce from 40 50 60 70 80 90 100 110 100% load in a 35°C ambient (worse case), to a situa- Load [%] tion whereby the load on the chiller is 50% and the am- Figure 1. Comparisonwith slide valve of performance of chillers. with inverter bient temperature is 15°C. As can be clearly observed, the EER for the unit at 50% load in a 15°C ambient is Figure 1 illustrates the first important point showing over double (~7) the value compared to when at 100% lower absorbed power of the screw compressor when load in a 35°C ambient temperature (~3). The thermal installed with an inverter, compared against a standard performances indicated demonstrate that this unit easily screw compressor with a slide valve. Chiller with in- qualifies for Class A efficiency categorisation. verter screw compressors are more versatile and highly efficient specialists used in chillers for air conditioning It is clearly important to know the ambient temperature, systems and industrial process cooling. the water temperature and the maximum load during the year (month by month) in order to assess the real With a slide valve the gas flow control is less accurate operating efficiency of chiller unit. than the inverter controlled counterpart. With a stand- ard compressor the capacity steps are static and prefixed 7 7 December (eg, 100%, 75%, 50% and 25%). With the inverter so- 6.5 December 9 6.5 lution, the screw revolution decreases proportionally January January 6 November 8 and the gas flow is modulated linearly. 6 5.5 November March EER 7 5 9 5.5 EERCOP - EER March October 6 COP 4.5 EER 8 5 4 July EER 5 EER 7 4.5 October COP - EER 4 3.5 6 COP 3 July 3 5 4 EER0 2 4 6 8 2 4 3.5 Month 40 60 80 100 3 3 Load [%] Figure 3. EER value of a chiller without free cooling. 2 0 2 4 6 8 40 60 80 100 Figure Month the EER value trend of a chiller without 3 shows Load [%] free cooling when operating with a water outlet tem- Figure 2. Performance for air cooled chiller. perature of 5°C. Figure 2 illustrates the real data performance for air This chiller is designed for 680 kW at full load. During cooled chiller. The COP is the ratio between cooling the warmer months of the season (June-August) the re- capacity and the compressor absorbed power input. The quired load is 100%, whilst during the colder period EER is the relationship between the cooling capacity of (November-March), when ambient temperature is much REHVA Journal – January 2013 51
  • Articles lower, the chiller load is estimated between 50% and Table 1. Weighting factors of part load efficiencies for 60%. It is interesting to observe that the EER in the hot- 8 calculating European Seasonal Energy Efficiency Ratio. ter months, during the worst demanding ambient condi- 7.5 Water leaving temperature (°C) 7 (constant) tions, has a minimum value of 4, whilst when the chiller Temperature [°C] Delta T full load (°C) 5 7 load is around 60%, the EER values are typically between Load (%) 100 75 50 25 6.5 Water Cooled Chiller 6 and 7, much higher than a standard chiller. All these val- 6 Condenser water temperature (°C) 30 26 22 18 ues refer to the maximum ambient temperature for each Air Cooled Chiller 5.5 month, so these EER are considered as a minimum. 8 Condenser air temperature (°C) 35 30 25 20 5 Weight in ESEER (%) 3 33 41 23 8 7.5 4.5 Temperature [°C] 7.5 7 4 Temperature [°C] 7 6.5 ple fan speed regulators to cut the phase applied to the 0 5 10 15 20 25 30 fan motor are currently widely used. With this method, 6.5 6 Time it is possible to decrease the rotation of the motor inter- 6 5.5 5.5 5 vening directly on the supply voltage. However, with the Outlet temperature use of inverters, which modulate the frequency from 20 5 4.5 4.5 4 to 50 Hz it is possible to reduce steadily the air flow and 4 0 achieve improved condensing control. 5 10 15 20 25 30 0 5 10 15 20 Time 25 30 Benefits obtained by the use of frequency variation with Time Figure 4. Outlet water temperature. respect to voltage variation are the following: Outlet temperature Outlet temperature Figure 4 shows the outlet water temperature trend. • Reduced noise levels Inverter control achieves much greater water tempera- This is a key point when using axial fans for refrig- ture control than is possible with a standard screw com- eration in the air conditioning sector, as air cooled pressor. It is evident that the water temperature fluc- chillers are widely used in residential, external ap- tuation is only +/- 0.5°C deviation from the set point. plications; when installed with fans operating from Furthermore the set point value is established more rap- a variable frequency drive, significant noise reduc- idly than on standard a chiller. tions up to 6 dBA for the same chiller unit are pos- sible (ISO3744). In the European market the adopted index to classify chiller performance is E.S.E.E.R. (European Seasonal • Lower energy consumption Energy Efficiency Ratio) and this is in accordance For low-medium speed (rpm) the frequency varia- with E.E.C.C.A.C. proposal (Energy Efficiency and tion allows reduced power consumption. However Certification of Central Air Conditioner). HITEMA the motor efficiency is completely utilized with all inverter driven screw chillers has E.S.E.E.R. of over 5. cooling load. A cut phase adjustable fan-motor has an efficiency ratio between 72−74% whereas the The formula used to calculated this is: same motor with frequency driver has a perform- ance ratio of 80%. ESSER= 0.03 x EER(100%) + 0.33 x EER(75%) + 0.41 x EER(50%) + 0.23 x EER(25%) HITEMA uses another innovative application around the air fans, that it consists in the use of a special diffuser The EER value (%) is the efficiency of chiller at 100%, on top of the fans (Figure 5), that allows: 75%, 50%, 25% of load under various conditions in ac- cordance with Table1. • Noise reduction of 6 dBA. • Energy Saving of 22%. For chillers with screw compressor installed with in- verter control and variable Vi compressor, the increase Centrifugal process pump (2-4 poles) achieved in the E.S.E.E.R. is around 15%. with Inverter Hitema proposes the application of the inverter control Axial Fans for Condenser with inverter on one or more centrifugal pumps, in order to obtain Hitema also offer the use of inverters applicable to the a non-dissipative regulation of power with the pump standard axial fans. To control the volume of air circulat- speed variation, depending on the heat load required. ed through the condenser in the air cooled chillers sim- (Figure 6 and Figure 7)52 REHVA Journal – January 2013
  • ArticlesFigure 5. Special diffuser   Figure 6. Inverter driven   Figure 7. Electrical board  for air fans. double pump. 140 with inverters for pumps. 120 B 140140 AHence we obtain significant results in energy saving 140 Head pressure [%] [%] 100 120120 BB Bas you trace the real load energy requirements without 120 AA Head pressure 80 A Head pressure [%] Head pressure [%]any additional loss or consumption being incurred by 100 100 100the process. 60 80 8080 40 60 6060To understand how the non-dissipative adjustment is 20 40 4040able to act in this method, we can consider the operat- 0 20 2020ing curve of a centrifugal pump. (Figure 8) 0 000 20 40 60 80 100 120 140 0 0 0 2020 4040 20 6060 40 80 80 Flow rate [%] 100 100 120 80140 60 120 140 100The intersection of the characteristic operating range for Flow rate [%] Flow rate [%]centrifugal pump with the typical flow-pressure curve Flow rate [%] Resistance curve at 100% Resistance curve at partial load Pump curvecan be used to identify the point of working regime Resistance curve at 100% Resistance curveResistance curve at at partial load Pumpcurve at partial load Resistance curve at 100% at 100% curve partial load Resistance Resistance curve Pump curve(point A for 100% of load). If the load in the system re- Figure 8. Operating curve of a centrifugal pump.quires a flow of 75% of the maximum by the regulation 140by the classic choke valve installed after the pump then 140120 140 140an additional pressure drop is artificially introduces and Head pressure [%] [%] 120100 120 120 B Bthe system must overcame a higher pressure drop (kPa A A Head pressure [%] Head pressure Head pressure [%]or m.w.c.) than is actually required by load (point B). 100 80 100 100 CFurthermore by moving the operating flow point, the 80 60 8080 Cpump efficiency is also changed, which then introduces 60 40 6060a further efficiency loss. 40 20 4040 20 20 20 0By adjusting inverter frequency instead, it follows the 0 0 00 20 40 60 80 100 120 140real load demand by altering the pump curve. (Figure 9). 0 0 0 20 40 60 Flow rate [%] 100 80 20 20 40 60 40 80 100 120 80 60 120 140140 100Varying the speed of the pump changes its actual oper- Flow rate [%] Flow rate [%]ating curve, which will move vertically downwards and Flow rate [%] Resistance curve at 100% Pump curve at 100% Pump curve at reduced speedthus we reach into the new operating point (point C) Resistance curve at 100% Resistance curveResistance curve at partial load curve at reduced speed Pump curve Resistance Operating Pump curve at speedResistance curve at partial load at 100%without any adjustment valve introduction. This results Figure 9.curve at 100% curve with100% Pump pump a real energy saving of 30%. ess cooling industries, commercial air conditioning andThe process pumps when installed with an inverter can data centres facilities. The optimum operation of refrig-effectively have zero starting current if the water flow eration equipment at partial loads is especially signifi-can be gradually increased up to the maximum flow, cant in condition where the medium annual ambientwhich again avoids potentially water hammer. The cor- air temperatures are between +5°C and +20°C, typi-rect management of the inverter location completes the cal for the vast majority of European conditions. Forfull system optimization. even lower ambient temperatures the combination of inverter technology coupled with that of free-cooling,Conclusion whereby chilled water can be produce using only fansToday there are many applications that require effec- energy, can be effectively used to produce chiller unitstive and innovative solutions to reduce the absorbed with even greater efficiencies than previously consid-powers requirements of refrigeration hardware in proc- ered possible. REHVA Journal – January 2013 53
  • News Eco design of energy related products – time for industry to wake up The scope of Energy using product directive Industry and other stakeholders may follow the progress was expanded to all energy related products in all stages, and during the preparatory studies stake- in 2009. The Eco-design directive allows the holder meetings are arranged, in principle open to all. Commission to develop regulation – with mini- However, generally speaking, industry is not really well mum requirements and mandatory CE marking prepared - only a few companies put enough effort today - for practically any product used in buildings. to follow up, and very few forerunners (typically large international companies) influence actively. All others (SMEs, branch organizations, other stakeholders…) are either totally asleep, or struggle with lack of resources (expertise, money, language skill, patience…) Jorma Railio Chair REHVA Technology and Research Committee Process of preparation of regulations Figure 1 shows the main phases of the preparations. Figure 2 shows the phases in more detail, including also T he Eco-design directive does not set bind- some features of the minimum duration of phases. The ing requirements on products by itself: it pro- whole process takes 55 months as a minimum, but in vides a framework for setting such requirements practice the whole process can take up to 10 years. through implementing measures. The Commission pre- pares implementing measures only for products which have significant sales and trade in the EU – generally over 200 000 pieces per year - and a significant environmental impact and potential for improvement. The preparation of implementing measures includes several stages ending Figure 1.PreparationofEco-designregulations – themain up in publishing the final regulation – meaning also that phases. 1. Working plan, 2. Preparatory study – Stakeholder the requirements for products defined in the regulation meetings, 3. Draft regulation – Consultation forum,   4. Regulatory Committee, 5. Final regulation. are exactly the same in all EU Member States. Figure 2. Minimum duration of different phases and steps of Eco-design process.54 REHVA Journal – January 2013
  • NewsHVAC-related Eco-design regulations “ENTR Lot 6 – Air Conditioning and VentilationAdopted HVAC related regulations Systems” –project was closed in July 2012. TheImplementing measures have been published and regula- “Document” page of the project*, now contains linkstions have entered into force for several product groups, to the complete final outcome of both “Ventilation” andincluding (Regulations can be obtained from Ecodesign “Air conditioning” parts of the study. Ecodesign – Lotwebsite -> Product groups page / Table at the bottom 20 and 21 for heating products final reports are nowgives links to the regulations in all EU languages) available online for local heating (Lot 20)**, and for cen- tral heating products (Lot 21)***.• Electrical motors - Commission Regulation (EC) No 640/2009 So, several product groups for heating, ventilation and• Circulators - Commission Regulation (EC) No air conditioning are subject to preparation of regulations. 641/2009 The difficulty is that a product with several functions• Fans (125 W to 500 kW power input) - can be subject to several regulations, e.g. one for heating, Commission Regulation (EU) No 327/2011 another or cooling, and a third one for ventilation.• Air conditioners and comfort fans - Commission Regulation (EU) No 206/2012 For Ventilation units, a Working Document containing a draft regulation of ecodesign and labeling, was sent to theRegulations in preparation relevant to HVAC (studies completed) Member States in October 2012. The document is based onENER Lot 1 Boilers - The scope of this lot includes the “Ventilation” parts of ENER Lot 10 and ENTR Lot 6.self-standing boilers. Technologies covered are fossil-fuel One key issue there is that the borderline between “residen-boilers, heat pumps and micro cogeneration up to elec- tial ventilation units” and “non-residential ventilation units”trical capacity of 50 W. This includes combination boil- has now been defined. Units with fans of less than 125 Wers providing heat for heating sanitary water. power input are regarded as “residential”, and larger ones as “non-residential”. The proposed regulation, however, givesThe draft ecodesign requirements would be introduced the manufacturer the possibility to decide the category ofgradually two and four years after entry into force of the the unit independently of the size. Labelling requirementsregulation. Annex II of the proposal includes informa- are prepared for “residential ventilation” only, because en-tion requirements and minimum performance stand- ergy labelling is primarily for consumer products.ards for seasonal space heating energy efficiency, waterheating energy efficiency, sound power level and nitro- 2012 ‑ 2014 working programme –gen oxide emissions. other activities for the future The Working Plan sets out an indicative list of product In the December issue of the journal, page 22, in groups which are considered priorities for the adoption of Mr Saikkala- Grönroos interview it was estimated implementing measures under the Ecodesign Directive. that the boiler regulations will be published in early 2014 – it should have been early 2013. List of “next” products subject to preparatory studies European Commission, Directorate-General for Energy,ENER Lot 2 Water Heaters. - The proposed require- launched in August 2012 a call for tenders with subjectments for water heaters, storage tanks, space and com- framework contracts for the provision of preparatorybination heaters include provisions for energy efficiency, studies, review studies and technical assistance. Thisstorage volume, sound power level, nitrogen oxide emis- framework contract is divided into three lots. The first onesions and product information. deals with preparatory studies and related technical assis- tance on specific product groups listed in the ecodesign ENER Lot 15 Solid fuel boilers and fireplace. - The working plans adopted under the Ecodesign Directive.scope of the proposed ecodesign requirements include The products mentioned in the call, as priority productsolid fuel boiler space heaters and solid fuel boiler com- groups listed in the second and subsequent ecodesignbination heaters (‘boilers’) ≤ 500 kW. Boiler combina- working plans, include steam boilers (<50 MW), smarttion heaters can be defined as boilers for space heating appliances/meters, positive displacement pumps, heat-in combination with supply of heat to deliver hot drink- ing controls and lighting controls/ and sanitary water. They were not included in thepreparatory study of lot 15, but have been included in * working document since no specific other lot cov- ** this product type. *** REHVA Journal – January 2013 55
  • News Substantial benefits of cogeneration to European economy As Europe places increased importance on About cogeneration industry in its economic recovery strategy, Germany highlights a major role for CHP in a modern low carbon industrial base. C ogeneration (also known as CHP or Combined A Heat and Power) is the simultaneous produc- new policy report endorsed by the German tion of heat and electricity. 11% of Europe’s elec- Ministry of Environment confirms that op- tricity and associated heat requirements today are portunities and possibilities offered by a mas- produced using this proven energy efficiency prin- sive backing of energy efficiency measures are much ciple. The estimated growth potential for cogen- greater than expected. It finds that EU 2050 climate eration is a further 110−120 GWe which will lead targets could be achieved through additional applica- to an improved environment and greater econom- tion of cogeneration to provide heat and power across ic competitiveness in Europe. Cogeneration units the industrial base. can be found in different sizes and applications: industry, households and tertiary sector and spans The report [1] ”Contribution of Energy Efficiency applications with capacities ranging from below Measures to Climate protection within the European 1 kw to hundreds of Megawatts. It is a highly ef- Union to 2050” published on 19 November 2012 ficient energy solution that delivers energy sav- was commissioned by the German Ministry of ings and substantial reductions in CO2 emissions. Environment from the Fraunhofer Institute for When seriously supported, as in Denmark, CHP Systems and Innovation Research ISI. It assesses has the potential to increase the energy production the potential role of energy efficiency among op- and transformation system overall efficiency from tions which will ensure that a shift to a sustainable a bare 33% (EU average) up to 65%. Realising the European energy system still complies with the con- potential of cogeneration in Europe will contrib- straints imposed by competitiveness and security of ute significantly to reaching the strategic climate supply. and energy goals, such as security of supply, energy efficiency and reduction of emissions. In 2050 Europe’s overall final energy demand could be reduced by 57 percent compared to the baseline with annual savings of 500 bn euros. The saving po- tential in industrial heat generation is primarily due About COGEN Europe to a further diffusion of CHP technology replacing units of separate heat and electricity generation as well as to efficiency improvements of separate and C OGEN Europe is the European association for the promotion of cogeneration. We repre- sent 70 organisations which are National COGEN combined heat generation technologies and consid- erable efficiency improvements in space heating tech- nologies. By 2030 and in the industrial sector alone, Associations, manufacturers, users, utilities and at least 9 Mtoe of savings result from CHP diffu- service companies. Currently around 100,000 sion and 10 Mtoe from efficiency improvements in Europeans are employed in the cogeneration sec- boiler and CHP technology. The total technical sav- tor. More info on ing potential mounts up to 44 Mtoe by 2030 and to 95 Mtoe by 2050 compared to the baseline. [1] REHVA Journal – January 2013
  • NewsNational energy efficiency policies in EU: The view of 750 expertsFollowing an extensive on-line survey and interviews learn from stakeholders, experts and relevant networkswith about 100 EU energy efficiency experts, the Energy how they see the progress of energy efficiency policiesEfficiency Watch Survey report has now been published. and their implementation in different sectors since theThe report tracks developments in each Member State. first NEEAP in their own country.In all Member States, political will and the poor under-standing of energy efficient are identified as key ele- Thus, the survey focuses on developments in the experts’ments for successful energy efficiency policies. own country, as interpreted by about 750 experts.T he Energy Efficiency Watch 2 Project (EEW2) The survey report is the first in a series of reports from aims to facilitate the implementation of the Energy the project. In early 2013, 27 national reports profiling Services Directive and in general energy efficiency policy developments in each EU Member State will bepolicies in the EU. It is co-funded by the Intelligent Energy published. The national reports follow a scientific analy-Europe programme and coordinated by EUFORES. sis from the screening of all EU NEEAPs.One key activity of the EEW2 project was an exten- For more information:sive survey on the implementation results of the first Energy Efficiency Action Plans (NEEAPs) in 27 Member States. The aim of the survey was to Figure: REHVA Journal – January 2013 57
  • News 50th Anniversary for SWKI REHVA congratulates SWKI (Schweizerischer Verein von Gebäudetechnik – Ingenieuren) with their 50th Anniversary on November 23, 2012. S WKI is REHVA’s national member association from Switzerland. On that occasion REHVA’s president prof. Dr.-Ing. Michael Schmidt handed over a small plaquette to express the warm relation between SWKI and REHVA. Prof. Dr. Yury Tabunschikov was granted by VDI, the insignia of Corresponding Membership Prof. Dr. Yury Tabunschikov was granted by VDI, the insignia of ‘Corresponding Membership’ during their executive board meeting on November 21, 2012. T his high VDI distinction is award- ed only in exceptional circum- stances. Prof. Tabunschikov – president of ABOK, REHVA’s national represent- ative from Russia – became his award amongst others for his outstanding re- search work in the field of construc- tional physics and building services, and his great contribution to come to international cooperation in our field. He did important translation work for VDI–guidelines, and REHVA diction- ary. Prof. Tabunschikov is Head of the Engineering Department at the Moscow Architectural Institute (State Academy). REHVA is proud to have him on board as delegate of ABOK and congratulates him (and Marianna Brodatch) with this Prof. Tabunschikov (left) receives VDI–Corresponding Membership, recognition. from prof. Dr.-Ing. habil. Bruno O. Braun, president VDI.58 REHVA Journal – January 2013
  • News SCANVAC Prize 2012 to Jørn Simonsen SCANVAC Prize 2012 was awarded unanimously by the jury to Mr Jørn Simonsen from DANVAC. Jørn Simonsen graduated from Technical University of Denmark in 1970 with a Master’s Degree in Engineering, specializing in indoor environment. Immediately after his studies he was offered a job as a project engineer in the Danish consulting engineering firm Carl Bro. In 1988 Jørn Simonsen joined Danvak, the Danish Society of Heating, Ventilation and Air Conditioning, as a member of the board of directors. After only two years he was elected chairman of the board and subse- quently made a substantial difference to Danvak. T here was unanimous agreement between the It was during this chairmanship that Jørn Simonsen and four presidents of the Northern HVAC socie- Danvak succeeded in reviving the informal HVAC exhi- ties, that Mr Jørn Simonsen, through his tireless bitions that were formerly held every second year. and outstanding work in the Danish and international HVAC industry, has contributed greatly to the HVAC In 1999 Jørn Simonsen became chairman of IDA industry and to the indoor environment field in general. HVAC, the professional HVAC network of the Danish The prize committee stated that the tribute was being Society of Engineers, and in 2003 he was again elected paid to “A man who has made a difference”. chairman of Danvak. Newsletter SCANVAC - SCANDINAVIAN FEDERATION OF HEATING, VENTILATION AND SANITARYSCANVAC - SCANDINAVIAN FEDERATION OF HEATING, VENTILATION AND SANITARY ENGINEERING ASSOCIATIONS IN DENMARK, FINLAND, ICELAND, NORWAY AND SWEDEN ENGINEERING ASSOCIATIONS IN DENMARK, FINLAND, ICELAND, NORWAY AND SWEDEN Scanvac Newsletter 2/2012 Online at • Coming events • Doctoral Theses • Awards • Articles – FinnBuild 2012 – a successful showcase for the Finnish construction industry – Second Swedvac Annual Autumn Meeting – EU regulations – update – Scanref Newsletter informs of Scandinavian research Scanvac – Ground Source Heat Pump sales increased 72% in Finland – ...and more REHVA Journal – January 2013 59
  • News Roadmaps for Poland, Romania and Bulgaria towards nZEBs T he Building Performance Institute Europe (BPIE) has researched and developed an ambitious road- map for Poland, Romania and Bulgaria which will help neutral new constructions. These national plans need to reflect the national understanding of nearly Zero- Energy Buildings, in line with local climate, economic the country progress towards the implementation of and cultural conditions, including strategies and policies nearly Zero-Energy Buildings and dramatically reduce for specific building categories. the national level of energy consumption and related carbon emissions. BPIE research recommends a holistic The studies build on the previous BPIE report Principles policy approach which can deliver on energy, climate for nearly Zero-Energy Buildings and evaluate through and economic goals. simulations whether the assumptions made earlier hold true for Romania, Poland and Bulgaria. The report en- European legislation on buildings (EPBD) and energy titled ‘Implementing nearly Zero-Energy Buildings, efficiency (EED) requires European member states to Towards a national definition and roadmap’ combines develop strategies on how to progressively transform a technical and economic analysis, based on specific na- their national building stocks into an energy perform- tional building data, economic conditions and existing ing and climate neutral built environment. Very low or policies. Different technological solutions - using vari- ‘nearly Zero-Energy Buildings’ will become mandatory ants of improved thermal insulation, energy efficient for all new constructions from 2020 onwards. To facili- equipment for heating, cooling, ventilation and hot wa- tate this process and to demonstrate the technical and ter and considering renewable energy generation - were economic feasibility of the nearly zero-energy standard, simulated for improving the energy performance of of- BPIE has undertaken a technical and economic analysis fices, single-and multi-family houses. The costs were set of the situation in three Central and Eastern EU coun- in relation to the actual practice in construction in the tries - Poland, Romania and Bulgaria - and developed country. Based on the simulation results, BPIE proposes holistic implementation plan for each. a concrete national definition for nZEB for the defined building categories, as well as policy implementation By 2013, EU member states are required to present to roadmaps towards 2020, when all new constructions the EU Commission their national definitions of nearly need to be nearly Zero-Energy buildings. Zero-Energy Buildings together with implementation plans towards more energy performing and almost CO2 More information at Sustainable Energy Week T he next edition of the European Union Sustainable Energy Week (EUSEW) will take place from 24 to 28 June 2013. Dates and procedures for organis- ing an Energy Day in 2013 will be provided shortly. Meanwhile, we are very pleased to announce the open- ing of the Sustainable Energy Europe Awards and the ManagEnergy Local Energy Action Award. Calling for best-in-class sustainable energy projects - 2013 Sustainable Energy Europe & ManagEnergy EU Sustainable Energy Week (EUSEW) is a core activ- awards - The European Commission invites all sus- ity of the Sustainable Energy Europe Campaign. Every tainable energy actors to submit their projects for the year hundreds of organisations and individuals partici- Sustainable Energy Europe Awards and ManagEnergy pate in the EUSEW. Local Energy Action Award. Through bottom-up efforts, organisers of EUSEW Share your accomplishments and show how they have Energy Days, events and activities connect directly with contributed to a more sustainable Europe. We look for- citizens and energy stakeholders at the local, regional ward to receiving your application. and national levels. The combined results of EUSEW efforts are helping Europe reach its energy goals. More information at www.eusew.eu60 REHVA Journal – January 2013
  • NewsProgress with Ecodesign regulations for air conditioningand ventilationThe third and final stakeholder meeting of thisproduct group (ENTR Lot 6) was held in Brusselsin spring 2012. The presentations and a lot of newbackground documents, and now also the min-utes of the final stakeholder meeting are availableat - for the slides fromthe meeting, go to takeholder comments on Ecodesign Study: Air con- ditioning and ventilation systems (ENTR Lot 6) are al- so available. The summary of comments (64 pages)shows that the industry is extremely interested in the topic and 3. Air conditioning condensing units [air-to-water, water-to-follow the preparation of the regulations closely. water, evaporatively cooled] 4. Terminal units to extract heat from the space to beThe products which are included in the preparatory study are conditioned • Fan coils1. Air conditioners 5. Heat rejection units means from the cooling system • Package air conditioner [air-to-air > 12 kW, water-to-air, • Dry coolers evaporatively cooled] • Evaporatively cooled liquid coolers • Split and multi split air conditioners [air-to-air > 12 kW, • Cooling towers water-to-air, evaporatively cooled] The report includes detailed information on the market of • VRF (Variable Refrigerant flow) systems (a split system the included products and the predicted increase in the total where the expansion of the power and energy use. • refrigeration occurs in the indoor units and not in the outdoor unit) [air-to-air > 12 kW, • water-to-air, evaporatively cooled] Read more at Sustainable Industrial Policy –2. Chillers for air conditioning applications [air-to-water, Building on the Ecodesign Directive – Energy-Using Product, Air water-to-water, evaporatively cooled, condenserless] conditioning products, Lot 6, Final report of Task 1, July 2012Koos Mast passed away just a few days after his 70th birthday OIn Memoriam n Friday 14 December tion between professional (HVAC) engineers all over 2012, J.G. (Koos) Mast Europe, he was especially proud of being elected a cor- MSc., Knight in the Order responding member of VDI, the German Engineering of Orange-Nassau, passed away Institute, He was one of the founders of the ‘REHVA just a few days after his 70th birth- Dictionary, our glossary in 15 languages with over day. Koos was a very active and en- 12 000 terms. Koos was President of TVVL’s organiz- gaged person within both REHVA ing committee for the “REHVA Annual Meeting 2009, and our Dutch member association Amsterdam”. He was awarded honorary fellowships of TVVL. He was President of the TVVL and REHVA. His consultancy firm, Smits van Dutch Society for Building Services Burgst ‑ The Netherlands, was REHVA’s first Dutch(1997−2004). Subsequently he was TVVL’s delegate to supporter.REHVA for many years. He was an Honorary Fellowof our federation, Chair of the REHVA Region One We all wish Lies Mast and her family the strength toGroup (2007−2011). He always expressed a strong pos- overcome their great loss. Koos will be sadly missed byitive influence on others, especially the youngsters in his all his friends in TVVL and the whole REHVA commu-environment. Koos was a real European in that respect, nity. He was a real gentleman, a true friend and a realhe was a sincere believer in developing communica- family-man, in every respect. REHVA Journal – January 2013 61
  • News The next ISH on March 12–16, 2013 at Messe Frankfurt I SH – The World’s Leading Trade Fair for The Bathroom Experience, Building Services, Energy, Air Conditioning Technology and Renewable Energies – of future-oriented building solutions in both horizontal and vertical terms. is the world’s biggest exhibition for the combination • Top Themes ISH Energy in 2013 are: of water and ener- • Efficient heating systems for gas and oil gy. With everything • Systems utilising ambient and geothermal heat from sustainable san- • Heating systems utilising wood itation solutions, in- • Thermal systems for the utilisation of solar energy novative bathroom • Electricity-generating heating systems design and ener- • Large-scale combustion systems, process heat gy efficient heating • Energy-efficient ventilation and air-conditioning technologies com- technology bined with renewa- • Energy-efficient room air conditioners and heat ble energies to envi- pumps ronmentally friend- • Energy efficiency and comfort in residential ly air-conditioning, buildings cooling and ventila- • High-end ventilation and air-conditioning tion technology, the technology world’s leading trade fair covers all aspects More information at REHVA Seminar during ISH in Frankfurt REHVA will organise a Seminar during ISH on Thursday 14 March 2013. The topic will be school ventilation. Please visit for more information. REHVA – ES-SO Guidebook Solar Shading is now available in five languages I n the authoritative series of REHVA Guidebooks, number 12 was published in 2011 under the title Ordem dos Solar Shading: How to Integrate Solar Shading in Enge nheir Sustainable Buildings. The content of the book has os been contributed by ES-SO. This book, available in its Sombreamento original version in REHVA’s bookshop ( Solar has meanwhile been translated in several languages and Como integra r o sombreame nto solar Somb ream tentáveis em edifícios sus is now also available in French, Swedish, Finnish and ento Solar Portuguese. National ES-SO members have worked on Wouter Beck (ed.) Dick Dolmans Gonzague Duto o the translations, together with the REHVA members And ers Hall Olli Seppäne n of each country. The books are for sale via the various Coleç ão Enge Finnish Solar Shading do Ar-Condiciona , Ventilação e rehva Associações Europeias de Aquecimento Federação das VA n.º 12 webshops of the ES-SO members ( or Manu al REH haria e Ar-Condicionado LISBOA rehva imento, Ventilação m 2012 via REHVA. The book is a great asset for educational eias de Aquec Associações Europ Brussels – Belgiu Federação das Washington, 1050 Rehva: 40 Rue XX Secretariado da -5129062 171 Fax: +32-2 Tel: +32-2-5141 .eu www.rehva .eu info@rehva purposes – and for our own members, of course. More translations are in the pipeline. Portuguese Solar Shading62 REHVA Journal – January 2013
  • HVAC & R productssolution partner for those whowant to live at the summit Nasuh Mahruki Y›lmaz Sevgül 2010 Everest Expedition sponsor CO2 Gas Coolers and Unit Coolers Friterm Starbox Condensing Units & Air Cooled Condensers Wet / Dry Coolers with Ecomesh Spray System & OEM Finned Pack Heat Exchangers & Steam Coils V-Type Dry Coolers CERTIFIED GEOMETRIES ID No F 2522 - 3/8” 03. 04. 065 Air Heating and Cooling F 3833 - 5/8” 03. 04. 315 F 4035 - 1/2” 03. 04. 316 Coils Using F 4035 - 5/8” 03. 04. 317 Blast Freezers & Air Coolers Water & Software FRTCOILS V.2 F 3228 - 1/2” 10. 09. 503Head office / Factory:‹stanbul Deri Organize Sanayi Bölgesi Dilek Sokak No:10 e-mail: info@friterm.comX-11 Özel Parsel Tuzla 34957 ‹stanbul / TURKEY web: www.friterm.comTel: +90 216 394 12 82 (pbx) Fax: +90 216 394 12 87
  • News Indoor environment in the focus of the 10th Ventilation Conference in Paris Guangyu Cao and Aimo Taipale VTT Technical Research Centre of Finland T he 10th International Conference of Industrial Ventilation ‑ Ventilation 2012 took place during Environment 17 ‑ 19.9.2012 in Paris, France. The Ventilation congress organised every 3rd year. Flow meas urement Ventilation 2012 Congress in numbers: Energy efficiency Design • 397 registered participants Occupational risk, Ventilation Noise • 25 countries from all 4 continents IAQ • 119 abstracts in the abstract book Air distribut ion • 69 papers in presented in 18 sessions Health Ventilatio n control In addition, totally 7 keynotes and 2 workshops were organized during the two and half days. Seven key- H Health Mechani cal note speeches were presented with regards to health, air distribution, noise, design principles, energy effi- ciency, occupational risk, ventilation control technolo- gies. Two workshops are: Improving the effectiveness of Figure 1. Main topics in Ventilation 2012 Conference. Local Exhaust Ventilation in the workplace and On-site measurements of ventilation air flow rates. The structure of topics in the conference is illustrated in Figure 1. The keynote presentation by Gerhard Kasper concen- President of REHVA prof Michael Schmidt made a trated on occupational health risk caused by nanoparti- keynote presentation “Energy efficient office buildings” cles in the workplaces. One big question in this area is the at the conference. size of particles relevant to health issues. Nanoparticles tend to agglomerate when released in the air forming Ventilation and health bigger particles, which still might have the nanoparti- Regarding health, Dr. Pawel Wargocki presented the cle properties related to health issues. This agglomerat- results of one study regarding the effect of ventila- ed particle size is also close to MPPS (Most Penetrating tion rate on health in homes. In addition, Mr. Otto Particle Size) which is most difficult to filter with me- Hänninen and Wargocki also introduced an EU project chanical filters. HEALTHVENT project, which is aiming at developing health-based ventilation guidelines in Europe. Figure 2 Ventilation rates shows the results of studies on the ventilation and health One study shows that minimum outdoor ventila- risks in homes, which suggest that increased ventila- tion rates in the building regulations of the most EU tion rates, also demonstrated reduced concentration of countries were in the range of 5.6 ‑ 11 L/s/person, ex- CO2, generally reduce health problems; only in few cases cept for Czech Republic and Slovenia (14 L/s/person) no effect or reverse effect was observed. However, the (C. Dimitroulopoulou, Ventilation 2012). The mini- study found that no specific ventilation system can be mum rate in the regulation of the Nordic countries is recommended to provide minimum ventilation rates. 7 L/s/person. Series of studies on ventilation and health in buildings with different ventilation systems would be desirable. Aerosols and air distribution In the future the emphasis will be occupant´s exposure In the study of aerosols and air distribution, Prof. Peter to harmful airborne impurities from both indoor and V. Nielsen showed the effect of RH on the transmis- outdoor sources. sion of exhaled aerosols, which presented in Figure 5..64 REHVA Journal – January 2013
  • NewsIt reviews that thetransmission of ex-haled gaseous sub-stances from one per-son to anther takesplace both in a di-rect way and via theroom air distribu-tion. Displacementventilation has a highventilation index, butit is also possible tohave stratified exha-lations in the occu-pied zone because ofthe vertical temper-ature gradient. Thiseffect may increasethe cross-infection,and the system can- Figure 2. Ventilation rate in homes and health. (P. Wargocki, Ventilation 2012)not be recommend-ed. This study alsoshows personalized ventilation built into a hospital bedis a new interesting possibility which can be used to re-duce the cross-infection problem without making sepa-rate rooms for each patient.Conclusions • Displacement ventilation has a high ventilation index, but it is also possible to have stratified exhalations in the occupied zone because of the vertical temperature gradient. (P. Nielsen, Ventilation 2012) • The minimum outdoor ventilation rates in the building regulations of the most EU countries Figure 3. Minimum outdoor air supply in EU office buildings. were in the range of 5.6 ‑ 11 L/s/person, (C. Dimitroulopoulu, Ventilation 2012) which is lower than recommended 25 L/s. (C. Dimitroulopoulu, Ventilation 2012) • Majority of European buildings, 91% of population of EU-27 countries, reside in areas where one or more outdoor air pollutants exceed the WHO Guidelines for Air Quality. Larger benefits can be achieved by ensuring that the indoor air complies to the air quality guidelines. (O. Hänninen, Ventilation 2012) • Ventilation/airflow rate is only the quantity of ventilation instead of quality, thus, the quality of airflow distribution should be paid more attention. • Increasing ventilation rate alone could not ensure Figure 5. The left figure shows the exhalation of 100 µm drop- a better indoor air quality without taking into lets in 35% RH and the right side shows the same exhalation account the pattern of airflow distribution, in surrounding air with a 95% RH after 12 sec of exhalation. (P. filtration and the outdoor air quality. Nielsen, Ventilation 2012) REHVA Journal – January 2013 65
  • Product news tilation systems Guidebook aims to renewal and purification Zephir³ by Clivet: air show that This tal conditions substantially influence health and NO: 14 at the centre of year round comfort and energy savings in the new and existing buildings useful Guidebook Zephir³ Clivet transformed the role of fresh air With presents criteria and methods on the in supply and purification within the HVAC system. all and maintain clean air handling systems for surem ality. system with active thermodynamic recovery system Zephir³ is the innovative air renewal and purification numbe and electronic filters, which maintains fresh air flow whilst satisfying the full heating and cooling require- The G ment. In this way it becomes the heart of the whole system, drastically minimizing chiller / boiler require- for the ments and minimizing electrical infrastructure includ- ing standby generators. to conventional systems, contributing decisively to im- The innovative active thermal recovery system recov- prove the class efficiency and value of the building. ers the maximum energy from the exhaust air all yearnt is intended to provide a holistic formulation of solution eliminates piping, insulation, and pump of the This gu round without any additional static pressure restrictions. The Zephir³ industrialized standalone / fully packaged Zephir³ also employs high-efficiency compressor with DC inverter technology and hot gas free re-heating. The requi- hydraulic NO: 15nstructional, technical and organisational by 80%. circuits, reducing the construction work and ope resultant system, which grants a COP up to 6.5, signifi-erved in the planning, manufacture, execution, characteristics Zephir³ is the most flex- and ind cantly out performs conventional fresh air systems. For all these intenance of Zephir³ can remove smoke / dust and bac- ible industrial applications, capable ofall commercial dark ga equivalent), ventilating and air-conditioning efficient solution for working in to- Incorporating high efficiency electronic filters (H10 and and energyquirementsgiving total purified air and creating the optimum tal harmony with all terminal systems: Fan Coils; DX; industri teria for ventilating and air-conditioningerve to protect human health. trated w fresh air condition, while reducing cost for ventilation VRF/VRV; Radiant and chilled beams. up to 30%. +39 0439/313235 – e-mail: - tools ar For further information: Barbara Casagrande, tel. Zephir³ allows a reduction in the consumption of pri- mary energy and CO2 emissions by 50% compared This guidebook talks16about in interaction of s REHVA Guidebook No. “HVAC the NO: 16 Sustainable Office Buildings – A bridge Heating, ventilation and air–conditioning. HVAC te between owners and engineers” talks about the interaction of sustainability and in sustainable buildings are described. This book Heating, ventilation and air–conditioning. list HVAC technologies used in sustainable of questions to be asked in various phrases buildings are described. This book also time. Differentofcase studies askedsustainable offic provides a list questions to be of in various phrases of building’s life time. NEW studies of sustainable office Different buildings are presented. .eu ● REHVA Office: 40 rue Washington, 1050 Brussels—Belgium 66 REHVA Journal –Guidebooks are January 2013 at or through RE available
  • Product newsWindow installation system for projectingwindows Key Benefits • The window can be fitted into the structural opening and the system provides a cavity closer around the window • The window can be replaced without the façade being damaged (renovation applications) • Fulfills the airtightness requirements of the upcoming EnEV 2012 regulation in line with the implementation of the EU buildingT • System certification according to . he illbruck Outside Wall Installation System ift Guideline MO-01/1 is suitable for new buildings and renovation projects, for EIFS and brick facades. The sys- • Quick and easy attachment and sealingtem consists of six components: the PR007 Window of the window (TP652 illmod trioplex+Installation Frame and the PR009 Window Panel – recommended)both made of recycled materials – as well as the PR008Insulation Wedge, TP652 illmod trioplex+, SP340Adhesive and AT140 Primer. The frame is glued to thewall, which takes very little time because no mountingbrackets are used. It’s safe because it securely adheres to Technical datalightweight materials and has a tested load-bearing ca-pacity of 200 kg per meter. • Driving rain tight up to1 050 Pa .The frame, the insulation wedge and, where applicable, following DIN EN 1027the panel create a kind of frame for the window, allow-ing for a secure, quick and standard sealing with illbruck • Airtight following DIN EN 12114 .TP652 illmod trioplex +. a < 0.1 m³/(mhdaPa2/3)Tests have proven that the illbruck system fulfills not • Pendulum impact test followingonly the airtightness require- ments of the upcoming DIN EN 13049 Class 5EnEV 2012 regulation in line with the implementa-tion of the EU building directive (will apply to all new • Load transfer for bonded system up tobuildings starting in 2019 or 2021), it is also the only 200 kg/mglue-based solution for outside wall installation that hasbeen certified by the ift Rosenheim. The results of the • Sound reduction following EN ISO 717-1 .sound insulation tests were also excellent, because the Rw (C; Ctr)= 43 (−2:−5) dBinstallation system does not reduce the window’s previ-ously determined sound reduction index. Further info see www.tremco-illbruck.comIn addition, the window can be replaced later on with-out damaging the exterior facade. REHVA Journal – January 2013 67
  • Product news The MEZ air duct profile complies with leak tightness classes C and D T o guarantee the quality of the air duct profiles An often-underestimated factor for the leak tightness (MEZ FLANGE SYSTEM) of MEZ-TECHNIK, of the air duct systems is the stability of the frame pro- compliance with leak tightness classes C and D file used (cf. CCI 2005; “Materialschlacht um jeden was tested by an independent TÜV-certified testing labo- Preis?” (The Battle for Materials at Any Price)). While ratory according to EN 1507 at the end of 2009. The re- many manufacturers have been using increasingly thin- sults went far beyond the required leak tightness values. ner sheet metal for the manufacturing of air duct pro- files for cost reasons, MEZ-TECHNIK relies on con- For decades, MEZ-TECHNIK GmbH has been supply- stant material thickness in the interest of quality and its ing air duct builders in Germany and abroad with high- customers. On the one hand, this leads to a considerably quality air duct profiles with and without injected sealant. higher stability of the air duct frame and thus to a higher Long before energy efficiency became the talk of the town, leak tightness of the air duct system, while, on the other the ventilation specialist of Swabian Reutlingen recognised hand, the required change from System 20 to System 30 the trend towards increasingly higher requirements on the or from System 30 to System 40 is delayed, which re- leak tightness and stability of ventilation ducts and the re- duces the material costs for customers and puts any extra sulting energy savings. Ahead of all its competitors, MEZ- costs for high material thicknesses into perspective. TECHNIK developed market-adapted air duct profiles with injected sealant, which it has continued to improve In the next few years, the trend towards increasingly over the past decades. Only now – more than 30 years after higher requirements on the leak tightness of ventilation the product innovation – have more and more competi- systems will certainly intensify. To be able to guarantee tors started to enter the market with imitation products leak tightness, it is important to use high-quality air duct and attempt to market them as an innovation. profiles. Particular attention should also be paid to the material thickness of the air duct profiles since its influ- The clear quality advance has been made possible not ence on the overall efficiency of a plant is quite often least due to decades of experience at MEZ-TECHNIK, underestimated. as well as constant investments into research and devel- opment – and all that at absolutely competitive prices. | www.mez-technik.de68 REHVA Journal – January 2013
  • Product newsIncreased energy efficiency with TELLUSClimate system from SwegonI n the spring of 2012 Swegon launched its new e.g. stand-alone air handling units or chillers. Especially multifunctional unit TELLUS on the international effective energy use occurs in spring and autumn at out- HVAC fairs Nordbygg and Mostra Convegno. door temperatures between 5−15°C, when there is a si- multaneous need for heating and cooling in the build-TELLUS is a complete, modular system product for ing. The smaller of the two energy demands is thenthe production of ventilation, heating, cooling and hot provided for free. Swegon expects TELLUS to save antap water. All these energies can be produced simulta- average of 30−50% of energy to acclimatize a building,neously or independently from each other, according to in comparison to traditional systems.the actual demand. The modular, compact design with all supply connec-TELLUS suits buildings between 600 m²−4 000m² due tions on one short side of the unit TELLUS allow ato its cooling capacity that ranges from ca. 25−82 kW, quick installation, the integrated controls make func-heating capacity between 12−60 kW and air volume tional start-up and commissioning easy and the holisticbetween 1 000−16 000 m³/h. TELLUS can be used for approach makes maintenance more effective.regions with outdoor temperatures between +45°C and−20°C and can be placed indoors or outdoors. The TELLUS design includes a couple of new tech- nologies that are patent pending, all for the purpose ofBesides acclimatized supply air, TELLUS provides cool- saving energy with multiple recovery systems, both oning water for comfort modules, chilled beams or fan- air and water side. Also all temperatures and pressurescoils and heating water for comfort modules, radiators are optimized in order to save fan, pump and compres-or under floor heating. sor energy.Due to the built in controls and integrated design In the next REHVA Journal a more complete overviewTELLUS can reach far greater energy efficiency than of Swegon TELLUS will be presented. REHVA Journal – January 2013 69
  • Product news BlowerDoor Measuring Systems feature high and consistent accuracy S ince 2012 BlowerDoor GmbH in addition to the calibration of the DG-700 pressure gauges has al- Technical Data (excerpt) so been offering the calibration of the BlowerDoor measuring fans using a calibration stand specifically de- veloped according to German Industrial and European Minneapolis BlowerDoor Standard Standard DIN EN ISO 5801. Per ring (open fan and rings A‑E) 3 values at 10%, 50%, and 90% of the re- BlowerDoor fan: spective flow-rate measuring range are each tested in the Capacity: chamber test stand at a pressure differential of 50 Pa. The 19 m³/h – 7.200 m³/h at a pressure differential of 50 Pa current environmental conditions, i.e. air pressure, tem- Power supply: 220 – 240 Volt, 50 Hz, nominal output perature, and relative humidity, are calculated into the < 600 watts, max. power consumption 4.5 amperes values measured in the testing chamber and those of the measuring fan according to manufacturer’s indications. Measuring accuracy: With open fan/rings A – C (flow rate approx. 80 – 7.200 m³/h) ± 4% of the mean, rings The structure of each ring set with five flow rings as “sin- D + E (flow rate approx. 19 – 80 m³/h) ± 5% of the mean or gle-orifice plates” is particularly beneficial to the accuracy. 1.7 m³/h (whichever is greater) The position of the pressure sensor as well as the geome- try of the fan and the rings have been developed in order Pressure gauge DG-700: to create a stable and reproducible velocity profile that Measuring range: - 1,250 Pa to + 1,250 Pa as far as possible is independent from the counter pres- sure (building pressure differential). Series of measure- Display resolution: 0.1 Pa ments have shown that BlowerDoor fans in longer use re- Batteries: 6 AA (optional power supply 220 – 240 Volt) main more accurate than what is usually required, within 1‑2%. BlowerDoor GmbH according to manufacturer’s Accuracy: ± 1% of reading or 0.15 Pa (whichever is greater) indications recommends an annual adjustment and man- For more information please contact ufacturer’s calibration of the pressure gauges and the cali- bration of BlowerDoor measuring fans every four years. Infitrometer from Retrotec T he Q5E Infiltrometer system uses the 2 hp fan and Retrotec’s unique mod- ular panel that looks professional, sets up quickly and allows for numerous test- ing configurations. Ideal for testing high-rise buildings one floor at a time or for multi-fam- ily and commercial buildings. Retrotec is the world’s leading manufacturer of blow- er door equipment, digital manometers, duct leakage test equipment, blower door testing software, and other tools for measuring building envelope performance. See more at REHVA Journal – January 2013
  • We don’t just make ventilation systems. We invent them. SwegonDiscover TELLUS. Our next pioneering INVENTILATION.Every commercial building has a need for fresh air, cooling, heating and tap water. Now all of this is available in one single modular systemproduct – TELLUS by Swegon. TELLUS is a complete HVAC and energy plant that can be placed indoors or outdoors. It produces and distributesdemand controlled acclimatised air, heating, cooling and tap water. All energies can be distributed simultaneously and independent of each other,according to the actual demand. The integration of all modules guarantees optimum control and interactive dynamic energy recovery.Discover TELLUS and experience the future of building technology today!
  • Books Review of the REHVA Guidebook No. 17 ‑ Design of energy efficient ventilation and air conditioning by Professor Tim Dwyer, Bartlett School of Graduate Studies,   UCL, London © 2012 | Originally published by the CIBSE Journal Design of energy A efficient ventilation new REHVA guide on energy efficient ventila- air conditioning systems, edited by Nejc Brelih, which tion and air conditioning is a great starting point marks the 17th booklet in the series. Despite the title, the for designers and consultants wanting to get up modest 100 pages quickly establish that this is not a de- to speed on the latest systems. sign manual but clearly a ‘starting point’, aimed at design- ers and consultants so that they can update their knowl- As REHVA heads into its 50th year, the Federation has edge on contemporary, state-of-the-art commercial sys- and air-conditioning expanded its series of guidebooks with the publication of the book Design of energy efficient ventilation and tems. Having provided a brief glossary of terminology, the book considers the state of the European building stock. systems Contents of the REHVA Guidebook No. 17 ‑ Design of energy efficient ventilation and air conditioning 1 Terminology Design of energy 2 Nejc Brelih (ed.) Energy and buildings in Europe efficient ventilation 3 Indoor environmental quality Olli Seppänen and air-conditioning 4 Air handling units Thore Bertilsson systems 5 Energy efficient fans 6 Mari-Liis Maripuu Air filters 7 Air-to-air heat recoveryLamy Hervé systems Nejc Brelih (ed.) Olli Seppänen 8 Alex Vanden Borre Demand controlled ventilation (DCV) Thore Bertilsson Mari-Liis Maripuu 9 Design and balancing of ductwork Hervé Lamy Alex Vanden Borre 10 Chillers and heat pumps rehva rehva 11 Pumps & Hydronics Federation of European Heating, Ventilation12 Electric motors and variable speed drives and Air-conditioning Associations Federation of European Heating, Ventilation and Air-conditioning Associations GUIDEBOOK NO 17 13 Solar shading equipment GUIDEBOOK 14 References NO 1772 REHVA Journal – January 2013
  • BooksAlthough there are different climatic conditions, the relating to the subject of each of the specific sections.common factor in Europe’s buildings (of which about The form of these naturally imply ‘rules of thumb’29% is non-residential) is that a substantial proportion that are bound to be keenly sought by students andis more than 50 years’ old, with nearly 60% having been developing practitioners alike and can, when prop-constructed prior to 1975. The implication is that the erly informed, give a useful steer to the uninformedprinciples conveyed in this book are potentially as im- or forgetful.portant in the operation and refurbishment of existingbuildings as they are for new build. The strength of these particular recommendations is that the reader can, and should, within a few hun-Providing some useful context, the proportion of built dred words, read the rationale and justification behindenvironment energy used in European non-residential them. The description of the application of equipmentbuildings (with buildings consuming approximately associated with air handling units (AHUs), and partic-40% of total European energy consumption) matches ularly filters, fans, heat recovery units and pumps, is Design of energytheir proportion at (just over) 30% of the total energy orientated towards minimising life cycle costs (LCC).use. The guide laments that there is no detailed break- There are some interesting examples comparing the ef-down of the energy use in European non-residential fect that face velocity (the velocity that the air passesbuildings, but looks forward to the outcome of two through an AHU) has on the LCC of AHUs, indicat- efficient ventilationongoing projects – available to be reviewed at and – which will provide thismissing intelligence. ing the benefits of larger section AHUs and in conjunc- tion with discussion on appropriate speed control of properly selected fans and pumps. and air-conditioningThe importance of being able to examine – and bench-mark – the nonresidential building stock with great-er discrimination is highlighted by wide variations The inclusion of a dedicated chapter on motors and speed control is to be applauded in what otherwise may be thought of a ‘mechanical services’ publication systemsin electrical energy use recorded in buildings across – the brevity of the material is still capable of provid-Europe. This will, of course, be influenced by climate, ing some important ‘keynote’ facts that may otherwisebut without proper differentiation it is almost impos- be marginalised. These core technical chapters pro-sible to assess relative performance of buildings, and vide a good grounding in the sensitivities of selectionto head towards the visionary expectation of net zero in centralised air conditioning and ventilation. Theenergy buildings laid out in the Energy Performance most extensive chapter covers on demand controlledof Buildings Directive (EPBD). ventilation (DCV), which contains some useful back- ground on the benefits of using such systems, togetherHaving set the scene, the succeeding 11 technical chap- with the practicalities of their impact on airflows intoters provide a somewhat eclectic mix of topics related rooms and the energy performance of building services systems. Oddly, the book ends Brelih (ed.)That is not to criticise, as it would be an unrealistic ex- Nejc with a chapter on passive so-pectation that this pocket-sized volume would provide lar shading – noOlli Seppänen doubt an important influence onthe breadth and the depth of a ‘Faber and Kell’ style building performance – but the space may well havetextbook. The contributions appear well informed and been used toThore conspicuous by their absence, cover areas Bertilssonthe book was also independently peer reviewed. including general room air Maripuu decen- Mari-Liis distribution and tralised systems, such as fan coils, chilled beams andAnd so turning to the technical chapters, (as listed in hybrid embedded systems. Some Lamy covered Hervé of these arethe box), these rightly open with the almost obligato- in other dedicated books in the series but, then again,ry review of indoor environmental quality – the main- Alex Vanden Borre so is solar shading. This guidebook provides a quick,tenance of which is the very reason for the existence well presented read of specific aspects of energy effi-of the industry represented by REHVA. The chapter cient centralised ventilation and air conditioning sys- rehvasuccessfully conveys the need to have a holistic under- tem technologies applied in commercial buildings. Tostanding of the FederationthatEuropean Heating, Ventilation such Air-conditioning Associations including parameters of define a wholly appro- cover and a potentially broad area, whilepriate internal environment, from the basics of tem- detailed discussions in such a condensed format, isperature and the influence of clothing and activity, challenging.through to outlining the impact on the economic per- GUIDEBOOK NO 17formance of the building. The layout of the subsequent Design of energy efficient ventilation and air-condi-chapters start with ‘Recommendations in a nutshell’, tioning systems is available at REHVA Journal – January 2013 73
  • Send information of your event to Ms Cynthia Depradel Events in 2013 – 2014 Conferences and seminars 2013 January 22 GEOTABS – Towards optimal design and control of Hannover, Germany geothermal heat pumps combined with Thermally Activated Building Systems in offices January 26 – 30 ASHRAE 2013 Winter Conference Dallas, Texas, USA February 8 – 9 ACRECONF New Delhi, India February 27 – Mar 1 World Sustainable Energy Days – the WSED 2013 Wels, Austria April 2 – 4 2nd IIR International Conference on Sustainability and the Paris, France Cold Chain April 10 – 11 European Biomass to Power Krakow, Poland April 11 – 12 CIBSE Technical Symposium 2013 Liverpool, UK April 15 – 17 3rd International Conference in Microgeneration and Related Naples, Italy Technologies in Buildings – Microgen III April 24 – 26 SB13 Munich: Implementing Sustainability – Barriers and Munich, Germany Chances May 9 – 11 5th International Conference on Amonia Refrigeration Ohrid, Macedonia Technology May 27 – 28 36th Euroheat and Power Congress Vienna Austria May 30 – 31 Energy Performance of Buildings and Related Facilities Bucharest, Romania June 3 – 8 eceee 2013 Summer Study on energy efficiency Toulon/Hyere, France June 7 – 8 The Latest Technology in Air Conditioning and Refrigeration Milan, Italy Industry June 16 – 19 11th REHVA world congress Clima 2013 Prague, Czech Republic June 19 – 21 Intersolar Europe 2013: Innovative Technologies and New Munich, Germany Markets June 22 – 26 2013 ASHRAE Annual Conference Denver, Colorado June 24 – 28 EU Sustainable Energy Week 2013 in Brussels Brussels, Belgium June 26 – 28 Central Europe towards Sustainable Building Prague 2013 Prague, Czech Republic September 25 – 27 5th International Conference Solar Air-Conditioning Germany September 25 – 29 International Conference on Sustainable Building Shanghai, China Restoration and Revitalisation October 3 – 4 CLIMAMED – VII Mediterranean Congress of Climatizacion Istanbul, Turkey October 15 – 16 European Heat Pump Summit Nürnberg, Germany October 15 – 18 IAQ 2013 – Environmental Health in Low Energy Buildings Canada October 16 – 18 Building Services for the Third Millenium Sinaia, Romania October 18 – 19 COGEN Europe Annual Conference & Dinner Brussels, Belgium October 19 – 21 ISHVAC Xi’an, China October 20 – 21 Energy Efficiency & Behaviour Helsinki, Finland Conferences and seminars 2014 May 13 – 15 11th IEA Heat Pump Conference 2014 Montreal, Canada August 31 – Sep 2 11th IIR-Gustav Lorentzen Conference on Natural Hangzhou, China Refrigerants – GL2014 October 18 – 19 CCHVAC Congress China Exhibitions 2013 January 28 – 30 AHR Expo Dallas, USA February 5 – 8 Aqua-Therm Russia 2013 Moscow, Russia February 26 – Mar 1 Climatizacion Madrid, Spain February 27 – Mar 1 World Sustainable Energy Days – the WSED 2013 Wels, Austria March 5 – 7 ecobuild 2013 London, UK March 7 – 9 ACREX 2013 Mumbai, India March 12 – 16 ISH Frankfurt Frankfurt, Germany March 21 – 24 SODEX ANKARA 2013 Ankara, Turkey April 8 – 10 ISH China & CIHE Beijing, China April 23 – 24 VVS Mässa Öresund – Trade Fair for Heating and Air Malmö, Sweden Conditioning November 4 – 8 Interclima+Elec Paris, France Exhibitions 2014 April 1 – 4 NORDBYGG 2014 Stockholm, Sweden March 18 – 21 MCE – Mostra Convegno Expocomfort 2014 Fiera Milano, Italy March 30 –  Apr 4 Light + Building Frankfurt, Germany May 7 – 10 ISK – SODEX 2014 Istanbul, Turkey October 14 – 16 Chillventa 2014 Nuremberg, Germany September 30 – Oct 3 Finnbuild 2014 Helsinki, Finland www.finnbuild.fi74 REHVA Journal – January 2013
  • ACREX 2013
  • REHVA Supporters REHVA Guidebooks are available at www.rehva.euREHVA Best Wishes for a Healthy and Prosperous year 2013 The Editorial Board members, the REHVA Board Members, the Editor-in- Chief and the staff wish all the readers a happy and prosperous year 2013.