What factor can significantly affect the efficiency of a gas appliance?

The efficiency of a gas appliance can be significantly affected by air intake and exhaust systems. Proper air intake is crucial for ensuring that the appliance receives the right amount of oxygen for combustion, which in turn promotes efficient burning of the gas. When the air intake is inadequate or improperly configured, it can lead to incomplete combustion, resulting in wasted fuel and increased emissions. Similarly, the exhaust system plays a vital role in safely venting combustion gases away from the appliance and the living space. If the exhaust system is blocked or not functioning correctly, it can lead to backdrafting, which not only decreases efficiency but also poses health risks due to the accumulation of carbon monoxide. Therefore, the design and condition of the air intake and exhaust systems are fundamental to the optimal performance of gas appliances.