When an appliance with a combustible chamber is located in the same room as a ventilation system return air opening, how close should the return air be to the open combustion?

The correct distance for a return air opening to be located from an open combustion chamber is 10 inches. This requirement is essential for safety reasons. If a return air opening is positioned too close to a combustible gas or an appliance with an open combustion chamber, it can lead to the risk of drawing combustion gases back into the living space.

Maintaining a distance of at least 10 inches helps ensure that the return air system adequately separates the potentially harmful combustion byproducts from the air that is being circulated throughout the room, promoting safer indoor air quality. This standard is intended to reduce the potential for accidents or harmful exposure to gases that may not be fully vented away during operation.

Understanding this distance helps in complying with safety standards in building codes and ensures the proper functioning of heating and ventilation systems while protecting occupants.