Venting Furnace And Water Heater Together

To determine the main flue size refer to figure 3 and locate the square inch area of each individual flue size.

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. 6 flue 28 27 square inches 8 flue 50 27 square inches total 78 54 square inches. In those cases the cold masonry cools the exhaust gases causing loss of draft as well as moisture condensation. The duct may be metal or plastic depending on the type of vent system.

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

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. 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. The solution is to use the masonry chimney as a chase for a b vent. When installed correctly this venting arrangement works with an 80 gas furnace or lower than 80 gas water heater.

Take a look at the two pics then. Another potential problem with newer category i vents involves furnace and water heater flues that are connected to masonry chimneys. Two appliances connected into single vent. A direct vent system pulls in.

This practice is common with standard efficiency 80 furnaces. The water heater vent is located below the furnace vent at the wye. They are connected at the wye.