Venting High Efficiency Gas Furnace Through Roof

Example of high efficiency furnace venting on a roof 2.

Venting high efficiency gas furnace through roof.

Installation guide for existing houses. Estimates the average life expectancy of a new gas furnace to be 15 years largely as a result. I a trying to reroute the venting that was done for a high efficiency furnace 3yrs ago. Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys.

As a result instead of using a conventional vertical venting system a high efficiency system uses pvc pipes that are connected to your furnace and lead out of the side of your home. It is classified as type bh venting. Venting for high efficiency gas furnaces materials due to the condensing nature of a high efficiency furnace its venting must be made of a material that is resistant to corrosion. That depends on whether you have a standard efficiency or a high efficiency furnace.

High efficiency furnaces produce high amounts of condensation moisture in the exhaust vent which is designed to run back into and through the furnace in order to drain out into either a floor drain or other approved draining system. The two systems use different venting systems. 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. Be dependent on the existing furnace system for venting.

These can include hot water tanks and other equipment related to the home. Also known as the type b this vent is operating on the natural air convection. If your furnace has an afue rating below 90 percent it will most likely have a flue pipe that goes up through your roof. If your furnace has an afue rating of 90 percent or above it will have a flue pipe that goes out of the side of your house.

These pvc pipes are connected to the furnace and expelled outside. A high efficiency furnace uses a different type of venting system because it extracts the heat that remains in those combustion gases before venting the resultant mixture of water and carbon dioxide. This structure generally uses the furnace vent pipe through roofbecause the b venting pipe is designed in vertical manner. The condensate that is left over from a high efficiency condensing furnace contains acidic water that would damage normal vents.

I am therefore attempting to vent straight up through the roof. This high efficiency venting system must be installed when you install the new furnace. In a great majority of cases plastic piping is used to vent high efficiency equipment. The venting was run to the side of our house there may someday be an addition this location.