The Importance of Getting a Pro to Seal Your Ductwork

The typical furnace or A/C blower in a residence moves over 1,000 cubic feet of air every minute. Professional duct sealing is what ensures all of that air gets where it needs to go. Leaky ductwork is a problem in most residences; in fact, the Environmental Protection Agency estimates that aging residential ductwork leaks an average of 20 percent of the conditioned air it conveys. In many homes, that figure is much higher.

Over the years, joints between spans of duct loosen and deteriorate and ductwork materials rust and corrode. Where proper duct sealing is neglected, two things happen—both of them bad:

  • Conditioned air gets out. Heated or cooled air escapes from supply ducts under positive pressure. When supply ducts leak, you’re paying high monthly bills to heat or cool your attic, crawl space or the inside of wall voids, instead of the rooms that are supposed to be kept comfortable.
  • Tainted air gets in. Return ducts operate under negative pressure. That means leaky returns actually suck air intothe system. Unfortunately, that air is drawn from unconditioned places you’d probably rather not be breathing, like the attic or inside of walls. It may be contaminated with mold spores or bacteria, or could introduce excessive humidity into living spaces.

Test, Then Seal

Since most ductwork is routed through areas inaccessible to the average homeowner, visual inspection of ducts is problematic. A qualified HVAC contractor can pressure test the ducts and calculate the extent of total leakage relative the total airflow through the system. While the ducts are pressurized, the technician can also pinpoint leaks for sealing.

Professional duct sealing involves sealing all joints with mastic and foil tape, then permanently securing the connection with metal screws. Any segments of ductwork that are collapsed or corroded beyond repair will be cut out and replaced. Where a large number of pinholes makes individual repair impractical, aerosol sealant can be injected to coat the interior of the ductwork.

Ask the professionals at Roth Heating & Cooling about pressure-testing and duct sealing to restore full efficiency and performance to your HVAC system.