Combustion Air Intake For Water Heater

Tankless water heaters can be vented in two ways.

Combustion air intake for water heater. Enclosed areas just as closets might need air ducts and extra air inlets. The process of burning of the gas is called combustion and it creates heat exhaust gases including highly poisonous carbon monoxide and moisture the water heater s ventilation system removes these byproducts from the home making it a critical safety feature. Gas tankless water heaters don t have to use indoor air for combustion. Where all air is to be taken from the outdoors divide the total input of all gas appliances in the space by 4000.

Water heater space heater range other total total 1000 step 2. Calculate the room volume. Around the water heater. In this example we ll say that the furnace has an input rating of 80 000 btu hr and the water heater has an input rating of 40 000 btu hr.

In decades past all combustion appliances for example gas fired water heaters furnaces and boilers took their combustion air from inside the house. These appliances were called atmospherically vented appliances the industry is now making the transition to sealed combustion appliances which take their combustion air from an outdoor air duct. As a general rule any gas heater which is tankless uses combustion air must have a minimum area of 10 000 cu. Power vent units use indoor air for combustion and simply vent the exhaust to the outside.

So the room needs to have a volume of 120 x 50 or at least 6 000 ft 3. Proceed to either part a part b or part c. Calculate the room volume. The vent when a residential gas fired water heater is installed in a closet the heater combustion gases must be vented to the outside of the residence and the fresh air needed for combustion must.

Increased heating system operating cost spending more on heating oil than necessary damage to oil burner components backpressure heat can destroy an ignition transformer. All water heaters that burn natural gas or liquid propane lp gas require a venting system. Air ducts required for combustion must be at least. Sizing combustion air openings step 1.

The models which need combustion air from the outside are required to have a second hose which is supposed to be put in. One combustion air opening must be installed within 12 inches of the water heater s upper enclosure and another within 12 inches of the lower. Total the column. We need about one square inch of un louvered unobstructed combustion air intake per 1000 btuh of the oil fired heating boiler furnace or water heater.

So the combined input rating is 120 when measured in 1 000 btu hr. Combustion air standard method alternate calculation method step 1.