We have a 2600 sq ft 1950s colonial in Massachusetts that, over the past 15 years, has had all new windows, blown in insulation on siding and closed cell foam in attic.  

I purchased an AirThings monitor mostly to check radon as didn’t recall ever doing that and that turned out great. However our carbon dioxide levels on the main open floor read 1400-1900 ppm consistently. I have moved the device around the house and hit 3,000 in a closed master bedroom as well.

Got a first quote for an ERV and it was more than I expected – 10k to install a RenewAire EV130 with registers in the two bathrooms and tying into the return of the air handler in the attic.

I have no frame of reference but had expected about 5k based on Google searches and forum reads. Also having looked at posts here, I’m not sure this is the best device for the money.

Would appreciate any guidance on this quote, suggestions on alternative devices and/or installers as well as thoughts on the necessity of an ERV given the CO2 levels.

I did call the two larger HVAC companies in our town and neither does ERVs so the installer I did found came from a Google search.

Thanks!