Originally Posted by adunephel
my house is one level, on a concrete slab, open floor plan (big open room, few doors), forced air heating/cooling (i believe). house inspector said i needed to have cold air returns. my furnace is located in a utility room with a completely slatted door.
could someone explain why i would have to have returns? (to me all the cold air gets sucked back up through where the air filter is).
A furnace running like yours is pulling a vacuum on the room the furnace is in. This can cause a down draft in the furnace stack and water heater stack.
If you have a natural draft furnace you could suck the flame out the front of the furnace . So you could have a fire risk and also a risk of getting carbon monoxide in the home If you check the size of the opening where the return air goes into the furnace. The free area going into that room has to be 4 times greater to not pull a vacuum. So check that slatted door and tell me how many sq. in. of free area you have. Paul