Torn Foil on a Heater Duct

Efficiency

• Foil ducts are not an efficient means of delivering heat throughout your home. They lose from 25 to 40 percent of the heat your furnace generates if you have not insulated them, and they often pass through unheated areas, such as the basement or attic, making the ducts vulnerable to heat loss. Torn foil increases the amount of heat loss, costing you more money.

Heating Duct System

• The heating duct system consists of two parts. One part carries heated air from the furnace to the various rooms in your home. The other part -- the return air duct -- pulls air from the room and recycles it back to the furnace. It is important that you frequently clean the area adjacent to the return air handler, as it will carry any dust, mold or other allergens back to the furnace for redistribution throughout your home.

Find the Foil Tears

• Examine the joints where two pieces of ductwork connect to each other. Look for tears near any kinks or turns in the duct system, including the “boot” where it connects to the registers. Check for damage from any animals that may reside in your attic or walls.

Repair Heating Duct Tears

• The repair method you use depends on the location of the tear. If the tear is within reach, use a two-step approach. Pull the foil together to close the tear, holding it in place with a fiberglass tape approved for heating systems. Apply a layer of mastic caulk to the area to completely seal the leak. If the leak is deep within your home, however, your choices are limited to tearing out the walls or hiring a professional contractor. Contractors use aerosol mastic to seal the tears.