Sealing Air Ducts

Second to insulating a home, sealing the air ducts is the most cost effective means of improving energy efficiency and comfort within your home. In a typical house, about 20% of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts.

Air Leaks

Leaks within the heating and air conditioning cooling air duct system are very costly, and unfortunately very common. Many times air ducts are not installed properly or without the proper support, and over time the joints, collars and boots pull apart.

Energy Efficiency

Air ducts are the pathways for conditioned air; they are responsible for regulating temperature and providing fresh air to the home. Leaks in supply air ducts will waste energy by allowing heated or cooled air to escape into unintended areas unconditioned areas such as crawl spaces or attics. While the openings of these leaks are often small, when the furnace or air conditioner is turned on it pressurizes the air ducts, making leak opening equivalent to 15 to 30 times their size.

Indoor Air Quality

Leaks within return air ducts can cause indoor air quality problems as they will draw in contaminants from unintended areas. Insulation particles and dust can enter your duct system, aggravating asthma and allergy problems. Sealing ducts can help improve indoor air quality by reducing the risk of pollutants entering ducts and circulating through your home.

Steps you can take to prevent leaks

Start by sealing air leaks using mastic sealant or metal tape and insulating all the ducts that you can access. Currently there are a number of duct sealant products available at local hardware store that can be applied with a caulking gun. After the caulking is applied to the joints use a chip paint brush to smooth the finish. Never use duct tape, as it will not last.

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.