How to Save Money by Sealing Your Air Ducts

February 22, 2017

Why Should a Pro Make Sure Your Ductwork is Sealed?

When most of us get our furnace or air conditioning unit serviced, we’re hoping that our homes will be comfortable and that all units are functioning properly and are in tip-top shape. But how often do we think about our air ducts?

After having a professional service your furnace or A/C, you expect your home to be comfortable and for the temperature to be even throughout your home. That won't be the case if you have leaky air ducts that go unchecked. Ask your HVAC professional to thoroughly inspect your air ducts and seal your ductwork as needed. This isn’t typically included in a routine servicing, so be prepared to ask about the additional cost of repairing and fixing any ductwork issues that your technician finds.

Follow along as we break down the following:

  • The impact air ducts have on home comfort
  • The benefits of duct sealing
  • The types of duct sealing methods

How Air Ducts Impact Home Comfort

Air ducts are designed to transport conditioned airflow to various rooms of your home. If your ductwork system is designed and installed to HVAC-industry standards, you should enjoy quality home comfort. However, duct systems in older homes were often designed and installed cheaply using inferior sealing materials that come unraveled with time. In the end, leaky duct seams or fallen ducts inhibit the possibility of balanced airflow and even temperatures. In other words, one area of your home will be too hot and another too cold.

Benefits of Sealing Ductwork

Fixing ductwork leaks ensures that your heating and cooling dollars are spent to keep you comfortable and not to condition your basement, crawl spaces, or attic. In addition to optimal comfort, you may expect the following benefits with professional duct sealing:

  • Greater efficiency: Leaky ducts lose up to 40 percent of heating and cooling energy before airflow reaches the living spaces.
  • Better indoor air quality: Ductwork that hasn’t been sealed can draw in contaminants from outside into your living spaces. It can intensify issues like musty basements and bring cold attic air into your living spaces. Sealed ductwork creates a barrier between the living spaces and unconditioned areas.
  • Less HVAC wear: Beware that heated and cooled air pours out of cracks in ductwork, forcing your furnace and A/C to pick up the slack by working harder. The extra load increases wear and the potential for more repairs.
  • Backdrafting: Backdrafting occurs when exhaust gases are pulled back into the home due to air pressure changes. Leaks in ductwork can create pressure changes and suck harmful fumes inside.

Different Types of Air Duct Sealing

There are many ways that an HVAC professional can seal air duct leaks. Having a properly sealed system of air ducts will make your home more energy efficient and safer. Here are two ways that air ducts can be sealed:

Mastic Sealing Method

Many HVAC professionals will seal a leaky air duct with mastic, a gooey material with a consistency similar to peanut butter. Sealing with mastic can be messy work and will be done by using disposable materials or a putty knife.

If you use mastic as your sealing method, note that gaps in the ductwork must be over 1/16" wide and gaps should be reinforced with fiberglass tape.

Duct Tape Sealing Method

So this is where the the “duct” in duct tape comes from! However, the tape you find in the hardware store is not the type of duct tape that you need to seal ducts. Duct tape used to seal ductwork must have a UL 181B label, which can be hard to find and long-term performance isn’t a guarantee.

There are different types of tape that an HVAC professional can use to help seal ducts:

  • Oriented polypropylene tape. To seal the the inner core of ducts and to repair the outer jacket, an HVAC technician can use oriented polypropylene (OPP) tape. This type of tape has a film-backing, unlike cloth-backed tape (which is what normal duct tape has). As long as ductwork joints using OPP tape are sealed with clamps, your home’s ductwork should be good to go.
  • Butyl duct tape. This type of tape is foil-backed, making it perform much better than cloth-backed tape, but it can be much more expensive. The adhesive on the foil-back is butyl-adhesive, which can be similar to some types of window flashings. This type of tape takes longer to dry out and will stay flexible, making it a better option than cloth-backed tape.

How to Choose Between Tape and Mastic

The HVAC technician inspecting and repairing your home’s ductwork will likely be the one to determine whether mastic or duct tapes are what’s right to repair the duct leaks. Talk to your technician to find out which duct sealing method they used so for future checkups, you can tell your technician what was used.

Leave Your Ductwork to the Pros

Do you think it’s time for a professional to look at your ductwork to ensure that there are no leaks? Leave it to the pros at Lozier Heating and Cooling. Our expert technicians can ensure that you aren’t wasting money on your energy bill because of leaky ducts and if you are, we’ll seal them as necessary. Reach out to us today to set up an appointment. At Lozier, we make you happy inside!

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