Furnace Closet Door Requirements

So the florida building code fbc g2406 and international residential code irc do not allow furnace installation in a bedroom bathroom or an any adjoining closet unless it meets these specifications that essentially isolate the furnace from the room.

Furnace closet door requirements.

The door assembly shall be installed with a threshold and bottom door seal and shall meet the requirements of section 504 1 2. All penetrations must be air sealed as well. Door assembly shall meet the requirements of section 504 1 1. Close off vents in door.

Combustion air for such installations shall be obtained from the outdoors in accordance with section 506 4. A furnace malfunction can cause a deadly carbon monoxide co buildup. When locating the walls be sure to allow enough space at least 30 inches to move around inside the furnace room so that maintenance and repairs can be performed on the furnace. The closet shall be for the exclusive use of the water heater.

Place the door across two sawhorses. More well judgment call but be sure the draft isn t so strong it is creating an air curtain across the discharge into the draft hood more likely on the water heater in my experience. Be sure to caulk around the seams to make a tight seal. In this arrangement the general rule is that your furnace room cannot be smaller than 50 cubic feet per 1000 btus of heat the furnace produces.

The door must have weatherstripping and a threshold to prevent air leakage between the closet and the house. Less isn t good especially in winter when drafts tend to run higher. Cut off the bottom few inches of the door with a circular saw to create a gap that allows air to vent into the furnace room. Refer to the furnace installation.

The key is that you have to install air inlets so that the furnace or water heater gets the combustion air it needs when it s running. Replace the door by reattaching the hinges. Once your combustion vents have been installed and the ceiling in the closet has been finished out you will want to close off any vents in the door. Unscrew the hinges from the furnace room door with a screwdriver.

Enclose any furnace cabinet with gypsum drywall which is fire resistant. This almost certainly means that you will need to add a basic vent to your closet so that it can bring in a flow of new air for combustion.