Vented wall furnaces must be located such that a door cannot swing within how many inches of an air inlet or outlet?

Vented wall furnaces need to be positioned in a way that ensures safe and efficient operation. To prevent potential obstruction or interference with the air inlet or outlet, it is required that a door does not swing within 12 inches of these openings. This distance is critical to maintain a proper airflow and avoid any hazards that might arise from the door blocking the air passage. Adequate clearance ensures that the furnace operates effectively, preventing the risk of improper combustion or airflow disruptions, which could lead to safety issues. This regulation aligns with safety standards aimed at ensuring that mechanical systems function without obstruction that could impede their intended operation.