Your AC unit is only efficient as long as it is in proper working order. For this reason, you should have your unit tuned at the beginning of every cooling season. While there is nothing quite like a professional's touch, there are things that you can do on your own to keep your system in good repair and save yourself a little money. Specifically, you should inspect for and repair leaks in your ductwork. 

Duct Repair

The seals on your ductwork will eventually wear out, and when they do, your ducts will start leaking. As air leaks out of your ducts, a smaller volume of air is available to cool your home, and your AC unit has to run longer than it should. In fact, leaky ducts can decrease your AC efficiency by up to 30%. Clearly, you should make repairs whenever it is necessary. If your ducts run behind the drywall in your home, you will not have the tools to make repairs on your own, so you will have to call in duct professionals. On the other hand, if you have exposed ducts running through your attic, your crawlspace, or through any unfinished portions of your home, you can make repairs with these steps:

  1. Turn your AC fan on at the thermostat
  2. Make your way to the ducts and light a stick of incense.
  3. Slowly guide the incense down the joints and seams in your ductwork.
  4. Watch for places where the incense smoke is disturbed. 
  5. Mark these spots with a permanent marker and keep moving so that you don't waste your incense. 
  6. Once you have covered the full length of your ducts, turn off your AC fan.
  7. Paint over each of the leaks you found with duct mastic. Make sure you apply a thick coat.
  8. Allow the mastic to dry before you turn your AC back on. 


If you have exposed ductwork, it likely is not protected by your home's insulation envelope. In this case, the outside air can heat up your ducts, which in turn will heat up the air running through your ducts, decreasing your unit's efficiency. Wrap your ducts with a reflective insulation to isolate the air in your ducts from the outside air and increase efficiency.

Ductwork is an important part of your AC system. It might not be what you first think of when you think of AC repair, but leaky ducts can still have a detrimental effect on the performance of your system. Not only will duct problems decrease efficiency, but they can cause premature wear and create premature system failure. Thus, wise homeowners will include ducts in their AC maintenance.

Visit Proctor Mechanical Corp for more information about AC repair.