Date
Inquiry
Energy Star for Homes performance includes a requirement that duct leakage cannot exceed 6 CFM to the outdoors. If a multi-family project has ducts running through interstitial spaces (e.g. between floors), is there any technique for isolating leakage to the outdoors? How should this be handled if the total leakage exceeds 6 CFM, but it\'s impossible to isolate the leakage to the outdoors?
Ruling
According to EPA, in a multi-family building, if ductwork runs into interstitial spaces, the total leakage should be limited to 6 CFM. The energy rater has some discretion. If the leakage only slightly exceeds 6 CFM but it\'s located within interstitial spaces that are air-sealed from the outdoors, the energy rater may choose to pass the building.
Internationally Applicable
Off
Campus Applicable
Off