HRV/ERV for finished basement?
Hi all. Wonderful site and I’ve enjoyed lurking and learning over the years.
We are planning to finish a portion of our basement – 200-400sqft. The inspector where I live, just west of Boston, says I will need some mechanical ventilation in the finished basement because the space does not have the minimum required natural ventilation. He suggested an ERV or HRV.
Possibly useful info: our house is a 1960s colonial. It’s been sealed and insulated but, we surely aren’t at the point where the house is too tight. We have forced hot water so there’s no existing furnace or ductwork to tie into. Basement walls are poured concrete and there is a walk out door in the portion we are not finishing.
Can anyone suggest a ventilation system/setup for a space this small? Even the smallest ERVs and HRVs I’ve seen are designed for much bigger spaces.
Does this requirement even make sense for a basement in a not-very-tight house?
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Replies
Joe, did you end up addressing this issue? I’m in a very similar situation (small finished space, walkout basement, no ducting, 1955 construction). I’m looking for a way to bring in fresh air and hopefully ventilate any residual radon and some smells from an adjoined crawlspace.
There are several options out there for small units. 2 units that are for thru wall are: Zehnder Comfoair 70, Lunos in wall system units. Fantech makes a unit that the specs show 42 cfm min airflow. I am not familiar with the Fantech model so I am not sure how that adjustment is made.
I've used Pansonic whispercomfort spot ERV for smaller places, install it the bathroom to replace the standard exhaust fan. It is pretty big and will take some space but does fit between joists 16" OC. You can also get the tandem exhaust kit for it which makes it pretty easy to install as it is only a single 6" hole to the outside. Don't install it in/over a shower as the electronics inside could get damaged.
The one thing to watch is the efficiency on it is pretty low, so if your code has minimum efficiency standards. If your code allows exhaust only for ventilation, the efficiency doesn't matter and will still be way better than the zero percent energy recovery of an exhaust fan.