Ducts are used to distribute conditioned air throughout houses with forced-air heating and cooling systems. In typical houses, about 20% of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts. The result is an inefficient HVAC system, high utility bills, and difficulty keeping the house comfortable, no matter how the thermostat is set.
Common duct problems include:
• Leaky, torn, and disconnected ducts
• Poorly sealed registers and grills
• Leaks at furnace and filter slots
• Kinks in flexible ductwork restricting airflow
Because ducts are often concealed in walls, ceilings, attics, and basements, repairing them can be difficult. But there are things you can do to improve duct performance in your house. Start by sealing leaks using mastic sealant or metal (foil) tape and insulating all the ducts that you can access such as those in the attic, crawlspace, basement, or garage. Do not use “duct tape,” as it is not long-lasting. Also make sure that the connections at vents and registers are well sealed where they meet the floors, walls, and ceiling. These are common locations to find leaks and disconnected ductwork.