Stop feeling guilty over inadequate duct sealing — it’s probably not your fault. To lower construction costs, most standard residential ductwork wasn't built to last the life of the home. Duct seams often aren’t sealed at all, or duct sealing is accomplished using ineffective methods like cheap cloth tape that disintegrates over time or sealants that degrade. Given the poor workmanship in your ducts, it's no wonder your household comfort level is not what it used to be. The good news is, you can restore interior comfort and save energy by having your ducts professionally sealed now.
Leaky ducts impact interior comfort in three ways:
- Leaky supply ducts deliver insufficient conditioned air to individual rooms to meet thermostat settings, making the rooms perpetually hot or cold. This supply deficiency also creates negative air pressure zones that suck outside air into the home through cracks and gaps in your home's exterior envelope.
- Leaky return ducts pull air into the system from unconditioned zones such as the attic or crawl space, offsetting the performance of your HVAC equipment. This oversupply of air creates a positive pressure in rooms, pushing conditioned air out through cracks and gaps to equalize pressure. Effectiveness of your HVAC equipment is further reduced and energy is wasted.
- Interior comfort is impacted by the infiltration of airborne contaminants caused by leaky ducts. Allergens such as pollen, mold spores and bacteria may be drawn into leaky ducts routed through unconditioned zones, then distributed throughout your living spaces.
These problems can be dramatized by having a Home Performance Assessment conducted for your home. This assessment utilizes sophisticated diagnostic instruments (blower doors, infrared cameras, etc.) and trained personnel to identify and isolate these conditions in your home. Furthermore, additional problems beyond the ductwork can also be found, too.
An HVAC professional will use these measures to identify and repair leaks:
- A visual inspection and a duct pressure test will determine the extent of leaks.
- Injection of smoke or fog into pressurized ducts can pinpoint the exact location of leaks.
- Joints and elbows will be mechanically secured. Rusted or corroded spans will be replaced.
- Application of mastic sealant will seal all joints, seams and leaks. Fiberglass mesh will be used to reinforce large holes before sealing.
- If pressure tests warrant, ductwork may be internally coated with an aerosol sealant to address extensive pinhole leaks.
Paul Wadsworth is the President and Owner of P.K. Wadsworth Heating and Cooling. For 37 years, Paul has been providing heating and cooling services to the Greater Cleveland area. P.K. Wadsworth has been a trusted Cleveland HVAC service company for 75 years. The company understand the area's construction and local heating and air conditioning needs. Paul has an MBA from the University of Michigan and a B.S., Industrial Engineering from Purdue University. He's been President of the Cleveland Air Conditioning Contractors of America and a founding member of the local chapter. Paul was born and raised in Cleveland and has been active in the local community. He resides in Cleveland, Ohio with his wife and two sons.
The opinions and statements contained in this article are for general informational purposes only and are not instructions. Only trained, licensed and experienced personnel should attempt installation/repair. The author assumes no liability for the opinions/statements made in this article. Any individual attempting a repair or installation based on this article does so at their own risk of loss.