Venting Furnace And Water Heater Together

Let s say you have a job where you combine a furnace or boiler 8 flue with a water heater 6 flue.

Venting furnace and water heater together.

Take a look at the two pics then. I know that irc g2427 3 3 4 allows these two appliances to join into a common vent connector. When installed correctly this venting arrangement works with an 80 gas furnace or lower than 80 gas water heater. This practice is common with standard efficiency 80 furnaces.

Another potential problem with newer category i vents involves furnace and water heater flues that are connected to masonry chimneys. The furnace is induced draft the water heater natural. They are connected at the wye. 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.

A direct vent system pulls in. Two appliances connected into single vent. All water heater venting systems use a vent duct or pipe also called a chimney or flue to bring exhaust gases from the water heater to the outdoors. I would venture to say that the vast majority of installs in this area use 6 b vent for a combination furnace water heater.

6 flue 28 27 square inches 8 flue 50 27 square inches total 78 54 square inches. The water heater vent is located below the furnace vent at the wye. Many homes are built with the water heater and furnace sharing the same combustion gases exhaust vent. The duct may be metal or plastic depending on the type of vent system.

The difference is that a power vent water heater pulls in combustion air from the space around the appliance then uses a fan to propel the exhaust through the vent. In those cases the cold masonry cools the exhaust gases causing loss of draft as well as moisture condensation. Lowering the btu rating of the furnace by even half would not require a change in the size of venting.