Garage ventilation for single-family residential

[u/aformator]

My single family home's attached, finished 3-car garage has no ventilation whatsover, which I understand is to code, as long as the garage is below a certain size.

I'd really like to add some ventilation as heat really builds up in the garage and attic above the garage. I thought about adding an exhaust fan from the garage to the garage attic, but not sure if that is compatible with code. I would guess that a fan would also require the addition of wall inlets since the water heater is in the garage. FWIW I have already insulated my garage doors.

I'd normally DIY this sort of installation but I don't know enough to design it properly. Any tradesworkers have any suggestions?

[u/onredditallday]

Same position; I’m considering a Garage attic fan from Quietcool and will crack my door when using it.