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Tips for Sealing and Insulating Your Ductwork

June 1, 2024

The ductwork in your home is responsible for transporting air from your HVAC system and dispersing it throughout your property. Unfortunately, leaks and gaps in ducts can lead to problems with your heating and cooling system’s efficiency as well as your home’s ventilation and air quality. 

Sealing and insulating air ducts help prevent many problems with comfort and energy efficiency. Below, Glenmont Air Conditioning & Heating shares valuable tips to ensure your ductwork always performs optimally.

Know How Uninsulated Ducts Affect Your Home

Sometimes people ignore their air ducts because they’re in attics, basements, and crawlspaces. As a result, ducts can develop wear which leads to gaps that allow chilled or heated air from the HVAC system to escape before reaching the vents in various rooms. 

Even if a gap isn’t present, air or heat loss can be a problem for ductwork if the system lacks insulation. According to the Department of Energy, uninsulated or damaged air ducts lose up to 30% of cooled or warmed air.

That loss can translate to excessive wear and tear, uneven cooling or heating, energy inefficiencies, and poor indoor air quality. Condensation buildup in uninsulated ducts can also contribute to rust, corrosion, and additional damage. 

Seal Ducts Correctly

If you detect signs of aging, wear, or improper installation in your air ducts, you want to seal them tightly, especially around the joints and elbows. When those areas don’t fit snugly, apply a nickel-thick layer of mastic sealant over them to ensure a tight seal. Using fiberglass mesh tape under the sealant is the best way to deal with large gaps. 

Consider Different Types of Duct Insulation

With insulation around your ductwork in unconditioned parts of your house like the attic or crawlspace, you can reduce how much energy waste and air loss your ducts produce. Here are several options to consider:

  • Fiberglass duct insulation uses an aluminum foil layer to block air leaks and moisture. It’s available in multiple thicknesses that you can cut to size.
  • Duct insulation sleeves are premeasured and sometimes come with adhesive strips to keep the material firmly in place. Material may include fiberglass, bubble wrap, or foam.
  • Batt insulation is affordable, and you can cut it to fit your ducts. 

Don’t Forget About Insulation R-Value

Not all insulation options have the same insulating properties. Always consider an insulation material’s R-value, which measures the material’s ability to prevent heat transfers from one space to another. A higher R-value means the insulation offers greater heat transfer resistance, making it a better choice for ductwork. 

Make the Most of Your HVAC System with Premium Ductwork Services

The ductwork in your Rockville, Maryland home plays a vital role in your indoor comfort that you cannot ignore. Ensure your duct system is properly installed, sealed, and insulated with help from our Glenmont Air Conditioning & Heating crew. Our qualified technicians have the skills and expertise to inspect, diagnose, and remedy air duct problems as the community’s top-rated HVAC contractor with more than 35 years of industry experience.

We guarantee your satisfaction with the quality of our work—call (301) 468-2665 today to request an estimate or book services. 

About The Author

Glenmont Air Conditioning & Heating

For over 35 years, Glenmont Air Conditioning & Heating has provided full-service HVAC repair, replacement, and maintenance in the Rockville, Maryland area. Contact us today to schedule service.