[68c10airstream]

Ogre is spot on, and i will add that with an attached garage consider the potential for an explosion with all types of furnaces except the sealed combustion models. My 25 year old sealed model has had zero problems, and 2 friends are on their 3rd hanging heaters from solvents, carb cleaners, paint fumes going up inside the heat exchanger and rotting them out from the inside out. Look at a grainger catalog and read the small print pertaining to this called "halogenated hydrocarbons"

Every shop i worked at the free hanging heaters were shot, poisoning us with carbon monoxide every day at a low level, and we were thinking initially it was qas from the car exhaust getting the cars in and out for repair. Argued with every owner to do the right thing and either replace or upgrade to sealed combustion. Even offered free labor to upgrade, but i guess i was a poor salesman on this. Obvious repairs that fell on deaf ears. Enough of my rant, good luck.