Venting Furnace And Water Heater Together

The solution is to use the masonry chimney as a chase for a b vent.

Venting furnace and water heater together.

Two appliances connected into single vent. When installed correctly this venting arrangement works with an 80 gas furnace or lower than 80 gas water heater. Let s say you have a job where you combine a furnace or boiler 8 flue with a water heater 6 flue. This practice is common with standard efficiency 80 furnaces.

The furnace is induced draft the water heater natural. Another potential problem with newer category i vents involves furnace and water heater flues that are connected to masonry chimneys. The duct may be metal or plastic depending on the type of vent system. In those cases the cold masonry cools the exhaust gases causing loss of draft as well as moisture condensation.

To determine the main flue size refer to figure 3 and locate the square inch area of each individual flue size. If you re replacing natural draft furnace no motor assistance for exhaust gases removal with an induced forced draft motor equipped appliance and your natural draft water heater remains connected to the same chimney flue pipe make sure that water heater vent pipe connection is y and not t type. I would venture to say that the vast majority of installs in this area use 6 b vent for a combination furnace water heater. 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.

The water heater vent is located below the furnace vent at the wye. They are connected at the wye. 6 flue 28 27 square inches 8 flue 50 27 square inches total 78 54 square inches. Lowering the btu rating of the furnace by even half would not require a change in the size of venting.

Many homes are built with the water heater and furnace sharing the same combustion gases exhaust vent. I know that irc g2427 3 3 4 allows these two appliances to join into a common vent connector. A direct vent system pulls in.