What is the maximum allowable height for an indoor combustion air opening from the ceiling of the room?

The correct response indicates that the maximum allowable height for an indoor combustion air opening from the ceiling of the room is 12 inches. This specification is crucial for ensuring proper ventilation and safe operation of combustion appliances. When the combustion air opening is located too high, it may not adequately supply the necessary air for combustion, thereby leading to inefficient operation and potential buildup of harmful gases.

Proper positioning of these openings helps maintain the balance of air needed for combustion processes. Regulations such as those found in the standards for gas appliances specify this limit based on safety and efficiency considerations. Hence, understanding and adhering to this requirement is essential for anyone working in gas installations to prevent dangerous conditions and ensure compliance with applicable codes and regulations.