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Make up air for bath fans

Pofarmer | Posted in General Questions on

I know that this has been done to death, but it doesn’t seem like there’s a a really great answer. We built a 2800 sq foot barn style home in Central MO. 2 x 6 advanced framing on a slab, insulated envelope with foam. Zip sheathing and roofing taped and sealed and plate caulked and sealed to the slab. 2 variable speed Panasonic bath fans set to 100 cfm.  They kick on with a motion sensor. These are really our main ventilation. Our contractor said he’s seen very few houses built tight enough to need and ERV or HRV.  Blower door testing is not really easily available, but we did everything in our power to make it tight. When both bath fans kick on you can feel it drawing air around the door seals.  When the fans go off, it quits.  This seems sub optimal to me, and tells me that we met our goal of building a very tight house. But I don’t really like that two bath fans are depressurizing the house that easily and I don’t think that this is great on the window and door seals.  What is my best option for return air? From what I gather HRV’s aren’t really made for the unbalanced load, and other than this the house stays comfortable and air quality seems fine. Thanks in advance.

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