ERV exhaust into attic
I’m in one side of a duplex with a vented, unconditioned attic in central Virginia. I’m wondering if it’s a problem to take the exhaust from an ERV and send it directly into the attic?
Rationale is that it would be one less roof or wall penetration, reduce amount of ductwork, and the exhaust should have already been conditioned by the ERV to be a similar temperature and humidity to the outdoor air, so it seems like it would be unlikely to cause condensation issues. Also, it would increase air movement in the summer, which seems like a possible benefit. But even as I write this I’m also realizing that it could add a slight pressurization to the attic which could drive air into the house, and it may also interfere with the natural eave to ridge air flow.
So guessing it’s not worth it, but what do you think?
thanks,
Ben
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
The one less penetration argument is weak because you have an entirely vented attic. It would be a bigger deal if the roofline was your air barrier. My vote is for routing it outside through the roof.
You could probably route it outside through the soffit. That gives you the benefit of not penetrating the building envelope without any of the downside of venting into the attic.
Thanks, I appreciate the input