What is required when mechanical exhaust interferes with the operation of an appliance?

When mechanical exhaust interferes with the operation of an appliance, providing air make-up is necessary to ensure proper combustion. This is crucial because mechanical exhaust systems can create negative pressure in a building, which may affect the availability of combustion air for gas appliances.

Air make-up means introducing fresh air into a space to replace the air being exhausted by the mechanical ventilation system. This helps to maintain optimal air pressure, providing the necessary oxygen for gas appliances to operate safely and efficiently. Without adequate air make-up, the appliances may become starved for oxygen, leading to incomplete combustion, potential increases in carbon monoxide production, and reduced efficiency.

In contrast, additional combustion air, increased pressure, or a backup power source do not directly address the issue of mechanical exhaust affecting the appliance’s operation. While additional combustion air might seem relevant, it doesn’t adequately compensate for the pressures lost due to an active exhaust system. Similarly, increased pressure would not resolve the imbalance created by the exhaust, and a backup power source is unrelated to the need for sufficient air supply in the combustion process.