Gas Furnace Venting Requirements

A conventional natural gas furnace will vent the dangerous combustion gases through a simple vertical exhaust system that is attached to the furnace.

Gas furnace venting requirements. The photo below shows typical combined furnace water heater venting. When the vent is withdrawing air from the house it expels the gas outside through the vent. The image will post after moderator approval. Two cases which can cause poor venting are the oversizing of the vent or reducing the.

Higher btuh furnaces produce higher flue gas temperatures. Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys. When installed correctly this venting arrangement works with an 80 gas furnace or lower than 80 gas water heater. Of the vent plus the furnace input and efficiency are factors affecting the temperature of the flue gases.

Sidewall vent direct vent direct exhaust systems for oil or gas fired heaters. This structure generally uses the furnace vent pipe through roofbecause the b venting pipe is designed in vertical manner. With a replacement high efficiency furnace the existing vent pipe does not work for water heater only because the vent is too large. Venting systems vent connectors slope in ft upward to chimney vent not smaller than appliance flue up to 2 sizes larger than appliance flue length depends on type for single appliance single wall 75 of vent height b vent 100 of vent height 18 inch diameter for multiple appliances 34.

Also known as the type b this vent is operating on the natural air convection. Venting requirements for gas fueled water heaters. Proper furnace water heater venting is an extremely important issue which depends on the performance of the house chimney chimney flue or other exhaust assemblies. In contrast modern high efficiency condensing furnaces exhaust much cooler gasses and need only plastic pipe materials such as pvc cpvc or abs for their exhaust vents some high efficiency furnaces also include a plastic pipe for intake area and all types.

The exhaust system typically uses metal venting often routed into a chimney stack to exhaust the combustion gases created in the furnace fire chamber. The vent pipe of your gas furnace plays an important role by carrying all toxic gases created during the combustion within the furnace out of the building. On 2020 04 05 by mod please try the add image button again cee. Consequences of improperly assembled vent pipes problematic chimney flue deteriorating chimney walls can be sometimes fatal fire and carbon.

On the other hand the higher the efficiency of a furnace the lower the flue gas temperature. You should know how to vent a gas furnace and get rid of the harmful gases for the health and safety of anyone living in your building. As noted 4yr old gas furnace vent pipes run straight across walk out basement and out the rear wall just below the window.