Anything that's not a reliable fuel fired device. The leakage all around a garage door as well as cubic volume of a double car or truck garage need to offer an adquate source of combustion air to any "B" vented unit. I have listened to some doozies. That is what https://preferred-content-languag10875.wikififfi.com/1455752/new_step_by_step_map_for_electric_garage_storage_lift