Furnace off garage

Am I correct in saying that the furnace isnt allowed to have return openings to the garage. Also doesnt the open vents break the fire wall?

The furnace didnt work & it is older. I Recommended a HVAC specialist. Wouldnt it be better if they selaed the outside at the garage and used the returns at the interior rooms? The closet had a opening into the interior but the access was sealed & blocked.

I did note the condensate needing to be discharged properly. Nice trench!!



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76906 Broadview Heights 022 (Small).jpg

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The furnace should not have a return in the garage.

Are you sure those weren’t combustion air vents instead?



They are combustable vents, I am not sure about the one at the bottom of the door. The ones in the door are for combustion. Doesnt this violate the fire wall?


The vent in the door is probably ok as long as the area the furnace is in, is sheathed with drywall. If it is not, than write it up.

I agree with Brian that the door louvers/vents don’t seem to be an issue if the mechanical closet/room has tight drywall for the fire separation (particularly at any pipe or duct penetrations). In fact model codes consider adjacent mechanical rooms with a common door part of the garage (which also kicks in the 18" ignition source elevation requirement). Note that there should be one louver/vent up high in addition to the one shown down low. And if there is an old door to the house sealed and/or blocked, it still needs to be a fire rated solid wood or metal door.

My guess about the grille below the door is that it’s a crawl space vent … that is assuming the house has a crawl space, and not a basement. Although I guess it’s possible it’s a furnace supply register (who knows, maybe the owner works in the garage a lot and figured he would add some heat by pissin in the wind … lol). But you are not suppose to have duct openings in a garage.

JMO & 2-nickels … :wink: