Venting High Efficiency Furnace Through Chimney

When the vent is withdrawing air from the house it expels the gas outside through the vent.

Venting high efficiency furnace through chimney. You cannot remove if chimney being used by furnace unless you get a high efficiency furnace. High efficiency furnace venting thru chimney pvc sch. So which type of venting system should your furnace have. Your furnace won t exhaust gases into your chimney anymore.

State not to use their pipe for combustion venting. High efficiency furnace venting uses two heat exchangers. Nor as a chimney liner. A conventional furnace vents these combustion gases through a vertical exhaust system that is attached to the furnace.

This fix often makes sense if you ve got a really old furnace or a big external chimney that stays cold throughout the winter. That depends on whether you have a standard efficiency or a high efficiency furnace. If your furnace has an afue rating below 90 percent it will most likely have a flue pipe that goes up through your roof. In comparing the venting of exhaust gases from a high efficiency furnace boiler or water heater with the venting of exhaust gases from a conventional heating system it will be immediately obvious that the high efficiency equipment exhaust is produced at a low enough temperature that it is vented through comparably small diameter plastic piping.

This structure generally uses the furnace vent pipe through roofbecause the b venting pipe is designed in vertical manner. The condition of the chimney is a factor because new super efficient gas furnaces do not vent up the chimney they are vented outdoors horizontally through a wall by a small plastic pipe. These high efficiency units use pvc pipe to pull air in for combustion and vent the by products to the outdoors. Also known as the type b this vent is operating on the natural air convection.

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. In fact most mfrs. Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys. 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.

For these reasons exhaust from a condensing furnace should never be vented through a standard chimney. Click to read further detail. Conventional furnaces use only one they use a two stage process. 40 pipe is not approved as a venting material for cat iii or iv by the pipe mfrs.

1 is the chimney being used to vent a furnace or does the house have a direct vent furnace vent out an exterior wall. In the first stage gas is burned to heat the first heat exchanger. The efficiency rating of a furnace is called afue annual fuel utilization efficiency.