On average your air ducts leak around 20 to 30% of your air conditioned or heated air. In order to help improve efficiency, it’s important to seal all of your air ducts joints and even insulate them if possible. Ducts that move air to-and-from a forced air furnace, central air conditioner, or heat pump are often big energy wasters. Sealing and insulating ducts can improve the efficiency of your heating and cooling system dramatically.
You’ll first want to focus on sealing the ducts that run through the attic, crawlspace, unheated basement, or garage. Their are a couple choices of sealant to use that have pros and cons. You can either use Mastic sealant or aluminum foil tape, below is a bullet list of some of the benefits of both.
Here are the benefits of both Mastic sealant and aluminum foil tape,
- Aluminum Foil Tape –
Often times referred to as, “plenum on a roll”, this is the less messy & easiest way of making sure your air ducts are properly sealed. It also means that it will tend to fail much faster due to dirt and oils coming into contact with the tape. If you do end up using tape, using mastic tape or butlyl tape, this will help improve the seal and stay in place much longer.
- Mastic Sealant –
With Mastic sealant, you are getting a much more effective way of sealing your air ducts, but it’s also much messier. The easiest way to apply this gooey substance is to use a standard paint brush. Depending on your leak, you may also need fiberglass mesh tape, make sure the tape matches the sealant.
After sealing the ducts in those spaces, wrap them in insulation to keep them from getting hot in the summer or cold in the winter.After, double check and look to seal any other ducts that you can access in the heated or cooled part of the house.