Refer to Table 7-1 in the 1997 UMC. In a building of unusually tight construction, an appliance is to be installed in an un-confined space. Combustion air to supply the appliances shall be taken directly from outdoors through two openings. Each opening shall have a minimum free area for all appliances requiring combustion of 1 square inch per ___ BTU/H.

Refer to Table 7-1 in the 1997 UMC. In a building of unusually tight construction, an appliance is to be installed in an un-confined space. Combustion air to supply the appliances shall be taken directly from outdoors through two openings. Each opening shall have a minimum free area for all appliances requiring combustion of 1 square inch per ___ BTU/H.