The benefits of professional duct sealing extend beyond simply increased comfort that results from ensuring all the conditioned air gets where it’s supposed to go in your home. In a forced-air system, leaky ductwork is a major source of high energy costs, as well as inconsistent temperature control and even poor indoor air quality. In residences more than 10 years old, air leakage due to deteriorated ductwork is common. While the homeowner pays the bill for 100 percent of the cooled or heated air produced by the system, as much as 30 percent of it may be leaking out into the attic, crawl space or inside wall cavities.
A professional HVAC contractor can perform a duct blower test to assess the extent of leakage as well as pinpoint the location of leaks. Utilizing pressure and airflow sensors inside the ducts and a blower to pressurize the system, a computer calculates the amount of air leakage from the ducts. Today, building codes in many municipalities require duct blower tests when new ductwork is installed or a central A/C or furnace is upgraded to a new model.
While the system is pressurized, the technician can inject artificial smoke into the ducts to reveal leaks and other duct dysfunctions that cause loss of airflow. A professional duct sealing procedure usually follows a multi-faceted approach:
- Collapsed sections of ductwork or those deteriorated beyond repair will be cut out and replaced with newly fabricated ducts.
- All joints between spans, at elbows and other junctions will be sealed with mastic or metal foil tape, then mechanically secured with metal screws.
- Where pinhole leaks occur in great number, liquid aerosol sealant can be utilized to coat the interior surface of the duct and restore airtightness.
- In addition to air loss, ducts routed through unconditioned zones like the attic or crawl space are subject to thermal loss due to the acute temperatures common in those areas. Duct insulation may be recommended in addition to air sealing to prevent heat gain or loss.
For information about professional duct sealing services in the Baltimore area, please contact us at Griffith Energy Services, Inc.
Written by Kevin Spain