ERV Exhaust in Conditioned Attic with Sealed Combustion Furnace
![](https://secure.gravatar.com/avatar/88e819fc6c60b1d1fbfbd31d2900f0c3?s=52&d=https%3A%2F%2Fimages.greenbuildingadvisor.com%2Fapp%2Favatars%2F200x200%2Fg.png&r=g)
I am planning on installing an ERV in my conditioned attic which also contains a sealed combustion furnace (Rheem R96V series)
I read it is good to put an ERV exhaust vent at the highest point in a house which would be in this attic. But I also read it is not good to install an ERV exhaust vent in the same room as a furnace. Is it OK to install an ERV exhaust vent in an attic that has a sealed combustion furnace?
When I say “exhaust” i mean the return grills that flow to the ERV and eventually to the outside.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
![](https://www.greenbuildingadvisor.com/app/themes/greenbuildingadvisor/dist/img/modules/detail-library/thumb1.png)
![](https://www.greenbuildingadvisor.com/app/themes/greenbuildingadvisor/dist/img/modules/detail-library/thumb2.png)
Replies
The concern of having the ERV extract or return in the same room as the furnace is the risk of depressurizing the space. If you can also provide ventilation supply air to the attic, the pressure should remain neutral and safe.
Unless you air sealed the attic floor, I can't see an ERV creating any measurable pressure difference. If you are worried, add a transfer grill in the hallway ceiling.