The easy answer is oxygen is a key element in combustion therefore your furnace needs air.
Furnace intake and exhaust separation.
This is roughly the equivalent of running a bathroom exhaust fan into your furnace s combustion chamber.
A gas furnaceneeds approximately thirty feet of air for every foot of gas used.
Irc 2006 section m1602 2.
Intakes must be protected against rain and pest entry with durable rust and rodent proof materials.
This is another affordable option for the heating solution.
Supplying makeup air can help natural draft appliances by compensating the effect of the powered exhaust appliances and equipment in the house including fireplaces exhaust fans ventilation systems clothes dryers and similar appliances and equipment.
Also known as the induced draft fan this one has a fan that is located on the end of the pipe.
The exhaust pipe has two 90 degree fittings at the top of the pipe which gives a 180 degree turn and the exhaust opening is pointed straight down.
Never pitch the exhaust pipe down ward toward the outdoors.
Since the exhaust pipe is running on a sidewall the fan works together with the furnace.
High efficiency condensing furnaces should not be vented into a chimney.
Provide at least a 1 4 inch per foot upward pitch for horizontal exhaust vent piping to allow the condensate to drain back down into the furnace.
The exhaust system typically uses metal venting often routed into a chimney stack to exhaust the combustion gases created in the furnace fire chamber.
It will draw in air for the combustion and then expel the fume outside.
The furnace in the furnace room is accessible for service.
3 wire nuts 1 snap bushing 1 snap plug 1 wire tie 1 condensate trap 1 condensate.
Wall intakes must also be 10 feet from any exhaust fan discharge outlet unless that outlet is 3 feet or more above the intake location.
At the top of the pvc pipe the intake has one 90 degree fitting so the opening is pointed straight out to the side of the vertical pipe.
My carrier furnace has two pvc pipes that go through the basement wall and up the side of the house.
However these combustion gases contain residual heat that is lost through the ventilation.
Furnace intake and exhaust pvc.
