We had one of these installed in the last couple of years and love it. We wanted to keep our CO2 lower, without leaving windows open and introducing dust/whatnot. Works well quantitatively and qualitatively.

FYI the "industry term" for these is an ERV or Energy Recovery Ventilator. (I think I've seen them referred to as Enthalpy Recovery Ventilator -- but I assume that fell out of favor since it's too pedantic for most people heh.)

If you get one, one tip is to ensure the air inlet is covered with a fine mesh screen. This cut the number in bugs in the filter 95%+. Also you can upgrade the filter from what's included to MERV13 or whatnot for better incoming air filtration.