What is the minimum clearance from grade level for the lowest portion of a floor furnace?

The minimum clearance from grade level for the lowest portion of a floor furnace is 6 inches. This requirement is essential for ensuring safe operation and preventing hazards that could arise from dirt, debris, or water accumulation around the furnace. Adequate clearance allows for proper airflow and prevents potential damage to the furnace and surrounding structures. It also helps in maintaining the furnace's efficiency and longevity by ensuring that it operates in a clean environment. When installations adhere to this clearance requirement, it promotes safety and compliance with mechanical codes that aim to protect both the equipment and the occupants of the space.