
• Range hoods. • Combustion air requirements for furnaces, water heaters and other combustion appliances. • Clothes dryers. • Location of return-air vents to furnace or air conditioning. • Imbalances of the HVAC air handling system. • Upper level air leaks: recessed lighting, attic hatch opening, duct leaks. WARNING Asphyxiation Risk This appliance produces carbon monoxide (CO). • The free opening areas (in square inches) of the chimney damper as shown in the following tables must be met. • User