Denver, Co. Home Inspection: Cobustion air duct

Clogged combustion air duct. Combustion air ducts provide outside air to your furnace and water heater. If furnaces and water heaters are in confined spaces they could be starved for oxygen to operate efficiently. Outside combustion air ducts must supply a minimum of 40 square inches.  Typically two 7 inch ducts are required one terminating 12 inches below the ceiling and one terminating 12 inches above the floor.  Recommend installation by a licensed HVAC contractor.

Denver, Co. Home Inspection: Cobustion air duct