My son's house has the gas furnace for the central heat in a 100 square foot or so room adjacent to the basement carport. At some point in the past, someone just knocked some holes in the wall and put some vents in to, we suppose, admit air for the furnace. He wants to simply put a vent in the entry door to the small room and let the furnace draw air through that. He would then repair the holes in the wall.

Does that seem like a workable idea?


Attachment 48826Attachment 48827Attachment 48828

I am no heating expert but I would say a big flat NO!
There are various features of a furnace that determine how it is to be vented, intake and exhaust.
First find the manual online, if you don't have it.

Personally I would ask for estimates from 2 licensed contractors. This is not stuff you mess around with. At the very least, you can be dealing with inefficiency and dirt getting into everything.

Looks like a poorly sealed Cold Air return. Are you talking about venting for combustion air? Louvered doors are good. A duct bringing air into the room from the outside would work. I believe the current code for solid doors requires 2 vents, one 12" from the floor level and a second one 12" from the ceiling of the room where the furnace is located. You could have 1 in the door and another above the door. If you have a 90%+ condensing furnace, no venting is needed as all combustion air comes from the outside of the house.

Yes, we are talking about air for combustion. That's the only reason I can think of for the placement of those vents. It sure looks like the work of amateurs. I'll mention the two vents you referenced to him. I'll also see if he has a manual for the furnace.