Potential impacts of         ductwork and envelope                leakage                     Rémi Carrié and Peter Wouter...
Ductwork leakageDuctwork can look like this                              2
It can also look like that                      Ductwork leakage classes Leakage classes are defined in EN 12237         ...
Field observations                 100%                        0.3             1         3        9          27           ...
Results on one test case   100%                     Nominal efficiency                                                    ...
Envelope leakage How does it work ?    Wind and stack effect increase the total ventilation airflow rate    If there is...
Background Airtightness can be characterized with leakage flow rate at 50  Pa divided by the building’s volume (not the o...
Typical n50 values ?               100%                                                                      Réf. RT 2005 ...
MININFIL project Large effort initiated by (CETE de Lyon) to help designers and  workers, both on the methodology and on ...
ConclusionsThe significance of envelope and ductwork leakage on energy use and ventilation system efficiency has been dem...
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Potential impacts of envelope and ductwork leakage by Rémi Carrié, INIVE, Belgium

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Webinar “Airtightness and ventilation perspectives in Romania“ June 21, 15:00-17:00 (Bucharest time)


AGENDA

15:00 Introduction of the webinar and objectives
Rémi Carrié, INIVE, Belgium

15:10 Global context of airtightness challenges and the TightVent Europe initiative
Peter Wouters, INIVE, Belgium

15:25 Potential impacts of envelope and ductwork leakage
Rémi Carrié, INIVE, Belgium

15:40 Exchanges with participants

15:55 Airtightness and ventilation in the Romanian regulation
Ioan Dobosi, REHVA, Romania

16:15 Progess needed on ventilation and airtightness in Romania
Horia Petran, INCD URBAN-INCERC, Romania

16:35 Questions & Answers

16:40 Open discussion
Chairperson: Rémi Carrié, INIVE, Belgium

16:55 Conclusion – Polling

17:00 End of the webinar


For more info visit http://www.tightvent.eu

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Potential impacts of envelope and ductwork leakage by Rémi Carrié, INIVE, Belgium

  1. 1. Potential impacts of ductwork and envelope leakage Rémi Carrié and Peter Wouters TightVent Webinar Airtightness and ventilation perspectives in Romania 21 June 2011 Presentation outline Ductwork leakage  Good and bad examples  Typical leakage rates  P t ti l implications Potential i li ti Envelope leakage  How does it work?  Possible airflow rate impacts Conclusions 1
  2. 2. Ductwork leakageDuctwork can look like this 2
  3. 3. It can also look like that Ductwork leakage classes Leakage classes are defined in EN 12237 3
  4. 4. Field observations 100% 0.3 1 3 9 27 81 243 90% France 80% Belgium g 70% Sweden Occurrence 60% Belgium and France: 50% 15% to 25% of ventilation flow rate 40% Sweden was leaking away (1999) 30% 20% 10% 0% Class D Class C Class B Class A 3*Class A 9*Class A 27*Class A PlusDuct leakage data from the SAVE-DUCT project (Carrié and collaborators, 1999). 21 systems tested in Belgium, 21 in France, 69 in Sweden. Why bother ? Fan flow is not adjusted Fan flow is to compensate leakage adjusted to obtain air flow rate correct air flow at t i fl t terminals  No increased energy  Energy losses by: losses  increased ventilation  Bad indoor air quality load  increased fan power demand 4
  5. 5. Results on one test case 100% Nominal efficiency From 80% down 90% Duct resistance: 5 m2 K / W to 43% ! 80% Duct resistance: 1,2 m2 K / W 70% 60% + increased fan 50% energy use 40% + increased ventilation load 30% 20% 10% 0% Class C Class A 3*Class ASE system with ducts located in unconditioned spaces. Reference : Proceedings of the BUILDAIR 2011 symposium, auhtors: Carrié and Leprince Envelope leakage 5
  6. 6. Envelope leakage How does it work ?  Wind and stack effect increase the total ventilation airflow rate  If there is a HR system, it may be short circuited + — Envelope leakage How does it work ?  Disturbance of flow patterns  BUILD TIGHT, VENTILATE RIGHT ! 6
  7. 7. Background Airtightness can be characterized with leakage flow rate at 50 Pa divided by the building’s volume (not the only indicator used in practice) : Airflow rate at 50 Pa n50 = Units : 1/h Heated volume 1 3 Airflow rate impacts Typical values of infiltration airflow rate, ninf n50 n50 n50 ninf  * 30 20 10 • Rule of thumb, see Drubul, 1988; Kronval, 1978. Rough approximation however useful to see orders of magnitudes Assumed Infiltration airflow Air change airtightness (n50, Infiltration rate divided by air rate (1/h) 1/h) airflow rate (1/h) change rate (%) 0,5 3 0,15 30% 0,6 3 0,15 25% 0,7 3 0,15 21% 0,8 3 0,15 19% 1 4 7
  8. 8. Typical n50 values ? 100% Réf. RT 2005 - Maisons 90% V/A = 1.4 m PassivHaus 80% réquence cumulée (%) 70% Réf. RT 2005 - Collectif, etc. V/A = 2.3 m 60% 50% 40% Réf. RT 2005 - Autres V/A = 2.5 m 25 30%Fr Maisons individuelles - 215 opérations 20% Collectif, bureaux, hôtels, étbt. enseignement ou sanitaire - 23 opérations Industries, salles polyvalentes ou de sport, etc. - 25 opérations 10% 0% 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 Perméabilité à 50 Pa (Vol/h)Source : Extraction de la base de données du CETE de Lyon - Juillet 2006 MININFIL project 8
  9. 9. MININFIL project Large effort initiated by (CETE de Lyon) to help designers and workers, both on the methodology and on the technical solutions MININFIL project 9
  10. 10. ConclusionsThe significance of envelope and ductwork leakage on energy use and ventilation system efficiency has been demonstrated in the pastTheir potential impact implies specific attention in the context of nearly zero-energy buildingsThere is obviously room for improvement: Probably in most countries outside Scandinavia for ductwork systems Probably in ALL countries for envelope airtightnessThere is a range of technical solutions available to overcome these problems 10

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