If your forced air system is consuming an excessive amount of energy to keep your home cool enough throughout the heat and humidity of summer, the problem could be the ductwork. In the average home, up to 20 percent of the cooled air produced is lost through ductwork leaks before it reaches the registers. Sealing ductwork properly can cut these losses and increase your HVAC system’s cooling efficiency. It’s especially beneficial when the ducting travels through any unconditioned and uninsulated areas of your home.
Duct sealing brings you some other big advantages:
- Enhanced comfort – A large loss of conditioned air makes it hard to maintain a cool and consistent temperature in the various rooms of the home. If the air is also stale and stuffy in some areas, sealing the ducts can help.
- Better air quality – Leaky ducts that run through unconditioned areas such as a crawl space, basement or attic can draw in dust, insulation particles, mold spores and other allergens. Fumes from the furnace and other fuel-burning appliances can backdraft and pull deadly carbon monoxide (CO) into the air distribution system. Sealing ductwork can keep these contaminants from circulating in the air you breathe.
A reliable HVAC specialist is your best source of expertise on effective duct sealing. If you want to tackle sealing up areas where your ductwork is easily accessible, the following tips can help:
- Check the duct connections. If you find that any are loose, reconnect them.
- With the HVAC fan running, hold up a smoke pencil or lit candle to locate leaky duct joints.
- Seal up leaks you’ve identified with mastic. Don’t use duct tape, as it won’t stand up over time.
- Use fiberglass mesh to cover any gaps wider than 1/4 inch, then apply the mastic sealant.
- After sealing, wrap any ducts located in unconditioned areas with R-6 insulation.
- Don’t forget to check for leaks around your air registers and fix them with foam or mastic sealant.
