This is assuming all the combustion air comes from that room.
Combustion air calculation for water heater.
Divide the total by 1000 of btu hr.
For pass through openings between adjacent spaces.
The reason i ask is every once in a while i run across a furnace in a room with out a source of combustion air no flues or louvers in the.
Now outside air can enter the dwelling and feed the combustion chamber and chimney reducing the negative pressure in that area without going through the return air system.
Combustion air defects at heating boilers furnaces water heaters diagnose signs of inadequate combustion air for an oil or gas burner dangers of carbon monoxide poisoning if there is soot production at gas fired heating appliances inadequate combustion air can cause dangerous carbon monoxide gas in buildings combustion air safety check procedure for gas fired heating equipment how to test.
The dual openings also limit the possibility of a single opening being blocked and starving the boiler or water heater for air.
Let s assume that we have 2 gas appliances a furnace and a water heater installed in a utility room or closet not in the garage different requirements apply bathroom or bedroom not permitted safety hazard.
This means the water heater uses outside air for combustion and not air used to heat or cool the building.
The room shall have not less than 1 cubic foot of volume per 15 btuh total equipment load.
With the second hose being located in the proximity of the furnace and hot water heater it can detect a negative pressure due to the air going up the chimney and open the damper doors.
Total the column.
The total net free area of the openings shall be equal to 1 square inch per 500 btuh of the equipment rating.
Direct vent water heaters always have access to an adequate supply of combustion air and will never create negative air pressure or function inefficiently.
Enter the input rating of all appliances in table 1.
In this post we ll discuss combustion air including what happens if we don t have enough and what the requirements are for enough there are two basic ways for your furnace to get its combustion air.
I know i m not supposed to be out there making calculations like this.
Water heater space heater range other total total 1000 step 2.
The air that your gas furnace and water heater and boiler needs in order to burn safely is called combustion air.
Wssc requirements used by this calculator.
Per 9 3 1 1 exception 2 dryers are not included total the column.
For all air from inside the structure.
Is there a quick and easy way to calculate how many cubic feet of combustion air a natural gas furnace in a room needs.
For air from outside.
I see many boiler rooms with the combustion air opening accidently blocked by either leaves or garbage or purposely blocked by wood or cardboard.
Calculate the maximum appliance.
Enter the input ratings of all appliances in table 1.
Where all air is to be taken from the outdoors divide the total input of all gas appliances in the space by 4000.
When connected to the outdoors thru.
Proceed to either part a part b or part c.
I m going to use just one configuration in this combustion air calculations example and it is a very common type of installation.