C ONTENTS      Vol 7 • No 3 June, 2011Cover Story              Building Management Systems              Green building des...
Green Bu i lding                                     Building Management Systems                                 Green bui...
A          brief on the construction        Environmental Quality as per LEED           done. These Smoking zones         ...
O         OGreen Bu i lding      Composite Average Particle Size Efficiency (%)              Minimum Final                ...
Green Bu i lding   affect indoor thermal comfort and                                                 system delivers fresh...
Green Bu i lding                                                       those zones that are densely     design values, via...
Cover story cooling_india_june_2011_by_samdarsh_nayyar_pt_pgpm_oct_10
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Cover story cooling_india_june_2011_by_samdarsh_nayyar_pt_pgpm_oct_10

  1. 1. C ONTENTS Vol 7 • No 3 June, 2011Cover Story Building Management Systems Green building design; Indoor air & ventilation Theres so much pollution in the air now that if it werent for our lungs there would be no place to put it all. - Robert Orben. This said phrase very rightly defines the need to monitor, control & maintain good Indoor Air Quality for the people working in closed environments. 44 CO2 an age old new environmental friendly refrigerant Along with the world, India is also in the process of phasing out ozone layer depletion substances (ODS) in both the production and end use consumption sectors. This is due to the increasing concern over the environment in recent times. People have become increasingly aware of the environment and the need to try and preserve the world in which all live. The biggest challenge is developing energy efficient products for day to day use in any applications so that ecological foot print of the product will be very less. The refrigeration and air conditioning systems are 24 not the exceptions to this trend. As per the estimation, more than one-third of world’s produced power goes into refrigeration and air conditioning sector.Articles Enterprise Building Management Buildings are gaining managements attention because of high and recurring energy expenses. No wonder Business Managers are responding to rising costs by bringing real-time data into high-level management decisions through a practice known as Enterprise Building Management (EBM). EBM enables the facility managers to use real-time information to deliver higher quality services at reduced costs and helps to bridge the gulf between the business and operational layers of the enterprise. 32 Cooling supermarkets the eco-friendly way To date, most refrigerated display counters and freezer cabinets in supermarkets use fluorinated greenhouse gases as their refrigerants. Leakages lead to refrigerant emissions which contribute to the greenhouse effect. Apart from this, if the refrigerant charge is too low, the plants’ performance drops, and replenishing incurs additional costs. Add to that the fact that the EU F-gas regulation, which came into force in 2007, increased the cost of using FCs and HFCs in refrigeration plants. All this 40 leads to the operators of such facilities having a very strong interest in alternative solutions. 6 June 2011
  2. 2. Green Bu i lding Building Management Systems Green building design; Indoor air & ventilation Theres so much pollution in the air now that if it werent for our lungs there would be no place to put it all. - Robert Orben. This said phrase very rightly defines the need to monitor, control & maintain good Indoor Air Quality for the people working in closed environments. - Samdarsh Nayyar 44 June 2011
  3. 3. A brief on the construction Environmental Quality as per LEED done. These Smoking zones Green Bu i lding sector indicates a major & GRIHA both. should besubject to Segregation challenge to the Indoor Air Quality is one the (specific area in the building environment. Globally, most essential components of Indoor located at periphery with fullbuildings are responsible for at least Environmental Quality. Under LEED height impermeable partitions40% of energy use. An estimated rating system, minimum indoor air and auto-closing doors and42% of the global water consumption quality performance is a prerequisite. independent HVAC system),and 50% of the global consumption Its intent is to establish minimum pressurization (room to beof raw materials is consumed by indoor air quality (IAQ) performance maintained at a negative pressurebuildings when taking into account to enhance indoor air quality in than the surrounding to avoidthe manufacture, construction, and buildings, thus contributing to the any infiltration), exhaust (100%operational period of buildings. In comfort and well-being of the fresh air and independent of theaddition, building activities contribute occupants, thereby resulting in building fresh air system) andan estimated 50% of the world’s air reduced absenteeism and increased dilution (separate ventilationpollution, 42% of its greenhouse productivity. system with higher ventilationgases, 50% of all water pollution, As per LEED, for mechanically rates of at least 60 cfm per48% of all solid wastes and 50% of ventilated spaces, it is imperative to person).all CFCs (chlorofluorocarbons) to the meet the minimum requirements ofenvironment. Section 4 through 7 of ASHRAE Indoor Chemical & Pollutant It therefore emphasizes the need Standard 62.1.2007, Ventilation for Source Controlto go Green. Acceptable Indoor Air Quality. For This aims at minimizing building While designing Green Building naturally ventilated spaces, they occupant exposure to potentiallywe broadly address the following must comply with ASHRAE Standard hazardous particulates biologicalareas: 62.1.2007 Section 5.1. On the contaminants and chemical• Site planning overall, a minimum of 10 cfm per pollutants that degrade air and• Building envelope design person should be met besides water quality.• Building system design (HVAC, meeting all other requirements. • Permanent entryway systems lighting, electrical and water Let us first discuss about a few (eg. grilles, grates or mats) at heating) sources of Indoor Air pollutants and least 10 feet long should be• Integration of renewable energy how the effects of the same can be installed in all the high-travel sources to generate energy mitigated. entrances/exits to capture dirt onsite. and particulates at the source• Water and waste management in Environmental Tobacco itself. a building Smoke Control (ETS • All spaces with exposure to toxic• Selection and application of Control) chemicals/gases like garages, ecologically sustainable materials Tobacco smoking not only has housekeeping or laundry areas, (materials with high recycled harmful effects on the health of Battery rooms etc should be content, rapidly renewable smokers but can cause serious properly exhausted with negative materials, materials with low health issues to passive non-smokers pressure with respect to adjacent emission potential etc) also. ETS comprises of Sidestream rooms. These spaces should be• Indoor environmental quality. Smoke coming out of the tip of a with auto-closing doors and Indoor Environmental Quality burning cigarette and Mainstream impermeable full heightusually covers the following aspects Smoke blown out by an active partitions. The minimumthough it varies for different rating smoker. ETS contains huge amount recommended exhaust ratesystems: of toxic and carcinogenic substances should be 0.50 cfm/sq ft with no• Environmental tobacco smoke thus exposing non-smokers to same air recirculation while a pressure control level of serious health risks.• Outdoor air delivery monitoring, Solution• Indoor Air Quality • The most recommended strategy• Use of low emitting materials is the prohibition of smoking on• Pollution source control the building premises. As is a law• Daylight and illumination now on complete ban on smoking• Noise and acoustics in public areas.• Controllability of thermal and • In case the building allows lighting systems. smoking, then provision of There are approximately 15 designated smoking zones withcredits pertaining to Indoor controlled environment has to be Fig. 1: Permanent Entryway grille June 2011 45
  4. 4. O OGreen Bu i lding Composite Average Particle Size Efficiency (%) Minimum Final both mechanical between 25 C & 30 O with optimum C, Resistance and natural condition being 27.5 C. It is essential ventilation). to maintain the required thermal 0.30-0.10 μm 1.0-3.0 μm 3.0-10.0 μm (Pa) (in. of water) The fresh air comfort conditions for building <75% ≥90% ≥90% 350 1.4 requirement can occupants as uncomfortable be estimated by conditions (too hot, too cold, and so Table 1: Requirements for MERV 13 Note: MERV is a filter rating established by the American Society of Heating, Refrigeration, & Air- the Ventilation on) have a negative effect on the conditioning Engineers (ASHRAE 52.2-1999, Method of Testing General Ventilation Air Cleaning Rate procedure productivity of building occupants. Devices for Removal Efficiency by Particle Size). MERV categories range from 1 (very low efficiency) to 16 (very high). (as per Section 6.2 of ASHRAE Comfort conditions for air difference of 5Pa on average and 62.1-2007) or conditioned spaces 1Pa at a minimum with the doors the Indoor Air Quality procedure For all Air-conditioned spaces, closed should be maintained with respect to neighbouring spaces. Zone Occupancy Outdoor Zone Outdoor Zone Zone Air Breathing Category Airflow Population Airflow Floor Distribution Zone • In mechanically ventilated Rate (Pz) Rate Area Effectiveness Outdoor buildings, all air-distribution units required required (Az) (Ez) Airflow like AHUs and FCUs to have per per Unit (Voz) supply air filters with a minimum person Area efficiency reporting value (MERV) (Rp) (Ra) of 13 or better. VAV-1 Office 5 12 0.06 500 1.0 90 Space Use of Low-VOC paints, adhesives and sealants Table 2: Ventilation Rate procedure. For an office space, as per ASHRAE, Volatile Organic compounds the fresh air requirement is 5 cfm/person + 0.06 cfm /sft. (VOCs) are carbon compounds (excluding carbon monoxide, carbon Thermal Comfort Standards the thermal comfort conditions dioxide, carbonic acid, metallic Indoor Air Quality is not restricted should be as specified in the NBC- carbides and carbonates, and to just pollutants and CO2 control 2005, BIS, Part 8 Building services; ammonium carbonate) that but also thermal comfort. Thermal Section 3, Air-conditioning, heating, participate in atmospheric comfort refers to a condition of the and Mechanical Ventilation; Section photochemical reactions. The thermal environment under which a 4.4.3 Inside Design Conditions, for compounds vaporize at normal room person can maintain body heat all working hours. temperature. Use of low-VOC paints balance at normal temperature Comfort condition for non-air- release significantly fewer polluting conditioned spaces toxins with only a slight odour Sl. No. Category Inside design conditions For all non-air- compared to conventional materials. conditioned spaces Since VOC emissions may contribute Summer Winter which are naturally to higher ozone levels, use of low- (1) (2) (3) (4) ventilated, as per VOC paints improves overall air O O O O GRIHA Criterion 14 to quality. 1 Restaurants DB 23 C-26 C DB 21 C-23 C achieve the required In place of urea formaldehyde, thermal comfort RH 55%-60% RH not less than 40% other adhesives for wood can be conditions the O O O O used to ensure that no formaldehyde 2 Office DB 23 C-26 C DB 21 C-23 C temperature should be 0 is released in the indoor environment. buildings less than 33 C and RH 50%-60% RH not less than 40% Phenol formaldehyde and melamine relative humidity should formaldehyde are used as substitute Table 3: Comfort conditions for air conditioned spaces be less than 70. These for urea formaldehyde. Source: Clause 4.4.3, NBC Part 8, section 3: Inside design condition conditions should be met for 90% of all Three Basic methods for without perceptible sweating. It is occupied hours (in composite, hot & ventilating buildings affected by environmental conditions dry and moderate climates) and Buildings can be ventilated in such as - eg. Air temperature, 60% of all occupied hours (in warm three basic ways. Radiant temperature, Humidity, Air & humid climates). • Mechanical Ventilation (i.e. speed and personal factors such as Demand Control Ventilation active ventilation) Metabolic rate, Clothing, preferences. Providing minimum IAQ • Natural ventilation (i.e. passive In India, according to NBC-2005, performance can solve some IAQ ventilation) Bureau of Indian Standards (BIS), problems by diluting contaminant • Mixed-mode ventilation (i.e., thermal comfort of a person lies concentration, but this strategy may 46 June 2011
  5. 5. Green Bu i lding affect indoor thermal comfort and system delivers fresh outdoor air to increase energy use. Hence, the several individual controlled spaces. need of Demand Control Ventilation Various methods of demand (DCV) systems. Moreover, coupled controlled ventilation in multiple with the building commissioning and zone systems are: measurement and verification • CO2 based demand controlled processes, these can improve IAQ ventilation alone while minimizing energy efficiency. • Ventilation Reset alone • Ventilation Reset plus CO2 based Basics in the form of air flow (cfm) in demand controlled ventilation Demand Signal as CO2 Based DCV response to This figure shows the typical e r r o r representation of single space CO2 generated by based Demand Controlled ventilation. set-point The CO2 sensor is installed in return temperature air path and Pressure-independent & room volume regulator units at outdoor air temperature. & return air intake. Demand signal for outdoor air VAQ Station intakes can be generated using A VAQ station ASHRAE standard 62.1-2007. is an effective • Here Demand Signal is generated solution for p r e s s u r e CO2 Based DCV Alone independent • Install a CO2 sensor in each volume control. individual controlled space & It can receive • Then determine how much demand signal outdoor air must be brought in at from both the air handler to satisfy the Occupancy, or critical zone. Critical zone is the CO2 Sensor for zone which has highest optimized IAQ requirement of outdoor air from as per ASHRAE several individually controlled standard 62.1 spaces, this zone is generally and Thermostat densely occupied and experience for effective in wide pattern of occupancy in the form of air flow (cfm) in room zone control. It will give airflow variations. response to error generated by • And then we reposition the space CO2 Concentration & outdoor air damper accordingly outdoors CO2 Concentration. to bring the necessary amount of Demand Signal as Thermostat for outdoor air to satisfy the critical Supply Air Control zone outdoor air requirement. Demand signal for in room or Ventilation Reset supply air can be generated using • Instead of installing CO2 sensor PID control algorithm & thermostat. in each zone, each VAV box It basically functions with controller senses the current differential of space temperature & primary airflow of each zone set-point temperature. With its use feedback in terms of 0-10VDC or (Vpz) and calculates its outdoor- we can categorize our HVAC space 4-20 mA analog signal and these air fraction (Zd) is equal to into several zones and also can get signals can be sent as a control current primary airflow divided desired temperature in their signal for air handlers drives. by maximum outdoor air required respective zone. for that zone. It behaves dynamically to current DCV - Multiple Zone • Then it determines the highest requirement of that space. Let’s discuss a multiple zone outdoor-air fraction reported • Here Demand Signal is generated system with DCV, where ventilation from several zone, which is said 48 June 2011
  6. 6. Green Bu i lding those zones that are densely design values, via a building occupied and experience automation system alarm to the widely varying patterns of building operator or a visual or occupancy. audible alert to the building • Zones which either occupants. Building Management are not densely occupied or Systems plays a very integral role in do not experience significant making buildings Green, and also variations in occupancy are are an essential part of Energy assumed to require their Audits, Commissioning and ventilation rate whenever Measurement and Verification they are occupied. processes. CO2 & ventilation rate to be critical zone. monitoring systems increase initial • And finally reposition the outdoor Control & Monitoring Indoor construction costs. But understanding air damper accordingly to bring Air Quality the criticality of IAQ control, capital in the required amount of outdoor A Building Management System costs & annual costs for air-flow air to satisfy the critical zone or a Building Automation System is a monitoring equipment maintenance outdoor air requirement. centralized control station for all & calibration procedures should be CO2 Based DCV with Ventilation Reset building services where the same considered offset by reduced This type of approach is inherited can be monitored, controlled, absenteeism, increased occupant from the two approach discussed metered, various parameters productivity, & reduced HVAC energy earlier. As we have seen in CO2 recorded, integrated and analyzed. use. As a part of the Building industry based demand controlled ventilation The same these days can be done it is our responsibility to design alone we supply outdoor air remotely also via web. environmentally-responsive depending upon critical zone which For IAQ control, it monitors/ buildings with superior Indoor is densely occupied, thus CO2 sensor meters CO2 and thermal comfort Environment and workspaces where installed in less critical zone are levels and automates the entire DCV people end up spending most time useless as per their utility in control system for auto-operation of VAVs, of their lives and to ensure healthy algorithm considered. Thus, we can VFDs and corresponding signals to future generations to our nation. imply ventilation Reset in less critical Air-conditioning plants to optimize zone instead of using CO2 sensor in as per load requirements thereby every zone, we install CO2 sensors resulting in tremendous energy ❁ at densely occupied space. Hence, savings and ease of operation. we get the desired result with One can configure all monitoring reduced number of CO2 sensors. equipment to generate an alarm • The best approach when the airflow values or CO2 • CO2 Sensors are installed only in levels vary by 10% or more from the Samdarsh Nayyar is the founder and managing partner of Green Horizon Consulting LLP - a firm offering Green Building consultancy (LEED, GRIHA etc), facilitation, energy simulation, third-party commissioning services, carbon foot-printing, and energy and water audits. A Mechanical engineer by education he is also one of the Directors in Sunil Nayyar Consultants Pvt Ltd, a leading MEP consultancy firm of India. He is a US Green Building Council- certified LEED APBD+C and a certified GRIHA Trainer and GRIHA Evaluator by GRIHA Secretariat, MNRE, Govt of India. He has been involved in various prestigious green building projects such as Commonwealth Games 2010 Village, Supreme Court of India Annexe, NIFT Role of Building Management Systems in IAQ Control & Monitoring Indoor Air Quality New Delhi to name a few. 50 June 2011

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