Final answer:
The combustion air for gas-fueled appliances provided by a mechanical air supply system should be supplied from the outdoors at a specific rate determined by the total input rating of all appliances located within the space.
Step-by-step explanation:
The question is related to the combustion air supply for gas-fueled appliances. According to the International Fuel Gas Code (IFGC), when the combustion air for gas-fueled appliances is provided by a mechanical air supply system, it should be supplied from the outdoors at a specific rate. This rate should not be less than a certain value, which is determined by the total input rating of all appliances located within that space. The rate is measured in cubic feet per minute per 1,000 Btu/h of total input rating.