For a 100 000 btu furnace gas fired or oil fired than a 50 square inch fresh air vent is required.
Gas furnace louvered door.
Note if a louver is used than this will decrease the size of the opening.
If you don t want to or can t use a louvered door here are your other options.
You can connect the furnace room to the rest of.
The heat that the furnace radiates may lead to a fire hazard.
This is where ventilation become important not the ventilation of the furnace itself but the ventilation of the closet space.
Combustion air can be drawn from adjoining spaces.
The heat can safely escape if there is space around the furnace.
Single panel full louvered doors.
Sometimes the door is sealed but a pipe comes into the closet to supply combustion air and that s ok.
A louvered door has horizontal slats for venting if the door is fully louvered over its entire surface then this will work as long as the combined input rating of the gas appliances is less than 175 000 btu hr.
Some furnaces allowed off sleeping areas with outside air and solid sealed fireproof door.
Door furnace 20 x 78 5 finished opening size 20 5 x 80 5 free air space 238 sq.
Do not install your furnace in a storage closet.
Electric furnace no combustion.
Fresh air is required.
Sometimes there is a small grill in the floor that some goof covered up with a piece of carpet that was not ok.
Insufficient clearance need metal door or fireproof door to reduce clearance requirements.
Therefore the above would reqiure 100 sq inches.
White finish is electrostatically applied baked on enamel.
Insufficient combustion air need outside air or a full louvered door or a standard door with high and low vents.