Given: A boiler room of tight construction contains three boilers. 2 rated at 1,000,000 Btu each, and 1 rated at 500,000 Btu. The minumum required area for combustion air is ____ square inches.

Given: A boiler room of tight construction contains three boilers. 2 rated at 1,000,000 Btu each, and 1 rated at 500,000 Btu. The minumum required area for combustion air is ____ square inches.