Combustion Air Louver Sizing Calculator

The combustion air supply is vitally important for the safe and reliable operation of fuel fired equipment. Combustion air can be direcly vented to the boilers, or boiler room air can be used as long as adequate makeup air is provided for the room. In the case that room air is being used, one or more louvers will be necessary to keep the room at a neutral pressure relative to the outdoors. The calculator below is used to determine the necessary size of louver(s) based on quantity of boilers, number of openings, and the net free area of the louver(s).

Please input the boiler model, quantity of boilers, number of openings, and the net free area of the louver(s). If additional fuel fired equipment is located in the same space as the boilers, please input the total input in BTU/hr.

Assumption: 1) Minimum net free area sizing is based on NFPA54/ANSI Z233.1