My shed/workshop’s heating and cooling load is less than the minimum BTU output of my mini-split, so I put together a balanced ventilation system on a budget to provide fresh air and keep the mini-split from short cycling.

Thoughts on my system? I’m in Virginia where we have a mixed-humid climate (4A).

The intake fan has a brushless motor which will run at 16 volts to produce 40-45 CFM through its 4″ duct, after taking into account the static pressure drop from a backdraft damper, a 12″x12″x2″ Merv 8 filter, and a 12″x12″x2″ Merv 13 filter.

The exhaust fan produces 50 CFM through a 3″ duct and should be around 45 CFM after accounting for its backdraft damper. 

I will run the fans for 15 minutes every hour using a timer switch. Any tips or gotchas I should look out for?

I know, I know. I could just open a window.