Furnace Pvc Vent Pipe Installation

A gas fired furnace for installation in a residential garage.

Furnace pvc vent pipe installation.

I ve read dozens maybe hundreds of high efficiency furnace installation manuals. Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys. This furnace operates best when return air temperature is between 55 f and 80 f. Doing so could cause heat.

When a furnace is installed so that supply ducts carry air circulated by the furnace to areas outside the space containing the furnace the return air shall also be handled by a duct s sealed to the furnace casing and terminating outside the space containing the furnace. The installation of the furnace wiring warm air ducts venting etc. 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. 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.

There s no problem with a one pipe system but the rules for venting are different. I began the installation of the new vent flue by purchasing schedule 40 pvc pipe in 2 and 3 diameters. Every single one of them had instructions for a direct vent and non direct vent installation. Continuous operation outside of this range may shorten furnace life.

The 2 pipe leaves the furnace and connects to the 3 pipe at the first turn. Do not install furnace in a location subject to continuous higher or lower temperatures. In the usa schedule 40 dwv pipe the usual stuff is still the standard there is talk this may change soon so stay tuned. The 3 diameter pipe is cellulose core which is approved by my furnace manufacturer.

Do not install furnace in any other position other than upflow. The national fuel gas code ansi. Must conform to the requirements of the national fire protection association.