Refer to the combustion air sizing Table 7-1 in the 1997 UMC. In a building of unusually tight construction, an appliance is to be installed in an unconfined space. Combustion air to supply the appliance shall be taken directly from the outdoors through 2 openings. Each opening shall have a minimum free area for all appliances requiring combustion air of one square inch per:

Refer to the combustion air sizing Table 7-1 in the 1997 UMC. In a building of unusually tight construction, an appliance is to be installed in an unconfined space. Combustion air to supply the appliance shall be taken directly from the outdoors through 2 openings. Each opening shall have a minimum free area for all appliances requiring combustion air of one square inch per: