Furnace Vent Pipe Through Roof

B149 1hb 00 natural gas and propane installation code handbook.

Furnace vent pipe through roof. Vent pipes provide this air by running outside the structure of the house. A conventional natural gas furnace will vent the dangerous combustion gases through a simple vertical exhaust system that is attached to the furnace. Gas fired water heating venting standards for canada see chapter 7 beginning at page 152 and also see combustion spillage beginning on p. Twist the roof s vent pipe clockwise one half turn with one hand while holding the gas furnace s vent pipe still with the other hand.

Plumbing vent pipes are connected to your drain system and are needed for water to drain properly. The condensing furnace produces condensed exhaust gases that contain water and carbon dioxide which together form carbonic acid that results in a corrosive condensate. If your furnace has an afue rating below 90 percent it will most likely have a flue pipe that goes up through your roof. Piping can be set horizontally to allow venting through a sidewall or vertical installation can also be undertaken to allow venting through the roof.

The exhaust system typically uses metal venting often routed into a chimney stack to exhaust the combustion gases created in the furnace fire chamber. Running a vent pipe out of the roof takes some careful preparation. The furnace uses an exhaust vent motor that pushes the exhaust gas through the vent pipe creating a positive static pressure in the vent. Push the male end of a new vent pipe up through the bottom of the roof flashing and set its female end on the male end of the vent pipe that connects to the gas furnace.

Also known as the type b this vent is operating on the natural air convection. If your furnace has an afue rating of 90 or lower it probably exhausts the gases though the flue pipe on your roof. Match the vent pipe to the furnace maker s recommendations either sheet metal or vinyl. When the vent is withdrawing air from the house it expels the gas outside through the vent.

160 in this example code. The vent cap or a roof assembly shall have a venting capacity not less than that of the pipe to which it is attached. If your furnace has an afue rating of 90 percent or above it will have a flue pipe that. Run the vent pipe up through the roof and install a metal or pvc flashing collar over it.

This structure generally uses the furnace vent pipe through roofbecause the b venting pipe is designed in vertical manner. That s because the combustion byproducts are in a gaseous form so the gases can float up through the flue pipe and out of your roof. The outer pipe draws air for combustion from outside and the smaller pipe occupies the inner position and is used to vent the exhaust fumes.