DIY Heat Recovery Ventilator ?

[mark]

Little cost/benefit needs to be done also to guide your solution.

Pushing out a little air with a low wattage fan and the energy cost to heat makeup air compared to the cost of a HRV unit or running a dehumidifier etc.

When my MH are on, I use a muffin fan to blow air up from the basement through my canopy (upstairs) then it just vents to the room (no worries about moisture and have a system volume of ~200g). Figure it probably costs something less than 10 bucks a year.

Electrical cost calculator.