Venting Gas Furnace And Hot Water Heater

The photo below shows typical combined furnace water heater venting.

Venting gas furnace and hot water heater.

The exhaust gas temperature of modern gas furnaces and water heaters is much lower than past appliances because much more heat is harvested so you waste less money up your chimney. Water heater ducts may lead directly outdoors or they may tie into a larger vent duct that also serves a gas or propane furnace or boiler in the home. Over the years we have received many questions regarding combined venting of furnaces and water heaters. 4 flexible chimney liner runs from basement up 1st floor and out to roof.

Atmospheric venting refers to a system in which exhaust from the water heater naturally rises out of the appliance s combustion chamber then travels up through a standard chimney style flue. 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. When installed correctly this venting arrangement works with an 80 gas furnace or lower than 80 gas water heater. Want to add a 40 000 btu gas hot water heater to same 4 chimney duct.

Rheem s prestige high efficiency natural gas combi boiler rheem s prestige high efficiency natural gas combi boiler provides an efficient continuous supply of domestic hot water used for faucets showers washing machines etc and provides hydronic space heating for residential applications such radiant floors baseboards hydronic air handlers etc. With a replacement high efficiency furnace the existing vent pipe does not work for water heater only because the vent is too large. This is called a common vent configuration. Traditional masonry chimneys were designed and sized to vent very hot flue gases from old coal wood burning or low efficiency gas furnaces.

Only thing hooked up to it is a 75 000 btu gas furnace with a powervent blower or direct vent. Common venting of gas appliances. The main concern has been whether a gravity vented water heater flue can be connected to the fan assisted flue of a plus 80 afue rated forced air furnace. The conditions explained in this post also apply to the wood burning appliances.

By michael casey and barry stone.