infiltration

Francesco Passerini

engineer

LEEDuser Basic Member

65 thumbs up

January 10, 2013

If I model a building where there is mechanical ventilation, how shall I consider the infiltration (i.e. "uncontrolled inward air leakage to conditioned spaces through unintentional openings in ceilings, floors, and walls from unconditioned spaces or the outdoors", see ASHRAE 62.1-2007)? Suppose that no blower door test was made. Generally I model a constant value of ACH, which I determine according to my experience, but shall I respect any particular document (e.g. an ASHRAE standard)? With Regards

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Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Thu, 01/10/2013 - 15:47

Infiltration can be modeled however you like but must be identical in both models. Unfortunately as far as I know no baseline has been established by ASHRAE so projects cannot claim savings for infiltration reductions. Is anyone aware of an attempt to establish infiltration baselines, perhaps as part of the development of 90.1-2013?

Julien Daclin

Head of Sustainability

Deerns France

LEEDuser Basic Member

24 thumbs up

Thu, 01/10/2013 - 16:09

Very interesting subject. The non-Residential Alternative Calculation Method (ACM) from the Califormia Energy Commission states that the infiltration rate should be 0.038 cfm per square foot of gross exterior partition (walls and windows) area for the zone. For new buildings, I agree with you Marcus that no savings can be claimed. However what about heavy renovation of existing buildings?