Take the confusion out of analyzing combustion air with a new tool from Code Calculators. The Combustion Air Calculator will minimize the outside air openings required for fuel-gas burning equipment by maximizing the use of interior air. Find out exactly how code compliant any installation is with the exclusive “percent compliant” display. Our Results section even provides solutions to reach 100% if your project is not compliant. Use the multiple projects feature to help separate and manage different jobs.