For a 25000 BTU gas-fired appliance in a single-story building, what is the minimum area required for combustion, ventilation, and dilution air openings?

For a gas-fired appliance, adequate ventilation is crucial to ensure safe and efficient operation. The minimum area required for combustion, ventilation, and dilution air openings is determined based on the BTU rating of the appliance. In this case, a 25,000 BTU gas-fired appliance requires a specific amount of air to ensure proper combustion and to prevent the buildup of harmful gases.

The correct choice is based on established code requirements and guidelines that indicate how much air opening area is necessary per 1,000 BTU of input heating capacity. Typically, recommendations suggest that for appliances in a confined space, at least 1 square inch of opening is needed for every 4,000 BTU of appliance capacity when intake air is provided from outside the building.

In this instance, calculating the required area leads to the conclusion that a minimum of 25 square inches is needed for proper combustion and ventilation for a 25,000 BTU appliance. This ensures that sufficient air is available for combustion and that any combustion byproducts can be effectively expelled, maintaining safety and efficiency.