Furnace Vent Pipe Through Roof

The condensing furnace produces condensed exhaust gases that contain water and carbon dioxide which together form carbonic acid that results in a corrosive condensate.

Furnace vent pipe through roof.

The furnace uses an exhaust vent motor that pushes the exhaust gas through the vent pipe creating a positive static pressure in the vent. The master flow 4 in. Goose neck vent in black can be used to cover exhaust pipes extending through your roof or for attic ventilation. 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.

This vent is designed to be used on 4 in. 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. If your furnace has an afue rating of 90 or lower it probably exhausts the gases though the flue pipe on 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.

This structure generally uses the furnace vent pipe through roofbecause the b venting pipe is designed in vertical manner. When the vent is withdrawing air from the house it expels the gas outside through the vent. A conventional natural gas furnace will vent the dangerous combustion gases through a simple vertical exhaust system that is attached to the furnace. Another problem is that flue pipes that go through the roof tend to be less efficient.

It s made of zinc coated galvanized steel for durability and reliability. 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. Match the vent pipe to the furnace maker s recommendations either sheet metal or vinyl. If your furnace has an afue rating below 90 percent it will most likely have a flue pipe that goes up through your roof.

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. Locate the vertical section of furnace vent pipe that passes through the attic. Run the vent pipe up through the roof and install a metal or pvc flashing collar over it.

The exhaust system typically uses metal venting often routed into a chimney stack to exhaust the combustion gases created in the furnace fire chamber. High efficiency furnaces take advantage of the heat in the combustion gases that are wasted in natural ventilation systems.