Energy efficiency is key when it comes to your HVAC system. How do you get the most out of your system while keeping energy costs low? What do you do when your energy bill is high? How can you increase the efficiency of your unit without investing in a new one?

After changing your air filters, installing a programmable thermostat and trying other countless ways to lower your energy bill and still had no luck, your ducts may be the problem. Duct leakage can affect the comfort of your home and take a toll on your wallet, but in many cases you can fix the problem yourself.

What is duct leakage?

Duct leakage occurs when the conditioned air in a house escapes the duct system through holes, loosely connected ducts or improperly sealed duct connections. According to ENERGY STAR, leaky ducts can result in a loss of 20 to 30 percent of the air that runs through an HVAC system. Duct leakage can not only lower the efficiency of the HVAC system, but it can also release dust and debris from the areas surrounding the ducts into the air and increase monthly energy bills.

How do you know if you have leaky ducts?

Duct leaks are known as the “quiet killer” in the HVAC world when it comes to HVAC efficiency, but here are some easy, at-home ways to tell if your ductwork is costing you money:

  • Your HVAC system is running, but some rooms are warmer/cooler than others;
  • Your energy bills are above-average;
  • Some of your rooms become dusty when you turn on your HVAC unit;
  • You see peeling sealant, metal tape or duct tape where holes may have been sealed at an earlier time; and
  • You have visibly crushed, tangled or kinked ductwork throughout your home.

Each of these are signs pointing to a costly duct leak that may be decreasing the efficiency of your HVAC system.

How do you find where your ducts are leaking?

The first step is to locate the source of the leakage. The best place to start is with any exposed ductwork you see. If you have removable tile ceilings (usually found in finished basements), remove the tiles and look for ductwork to inspect. Look for poor connections at joints, holes caused by wear and tear, and loose, crushed or tangled ductwork to find the most likely culprits.

If you don’t see any of those obvious signs of leakage, use the smoke test to locate problem areas. Turn your unit on to its fan setting and light a stick of incense or a candle. Pass the smoke from the incense or candle over the exposed ducts in your home, starting with the places where your ducts connect to the main unit and the areas where two ducts are joined. If the smoke is blown away or pulled in to the unit, you are experiencing duct leakage.

How do you fix the leaking ducts?

Once you locate the leakage point, there are some simple solutions for fixing the leak.

  • Seal your joints- Seal any holes, loose connections or leaky joints with duct mastic sealant or metal duct tape. Unlike traditional, cloth-backed, rubber duct tape, these sealants are long-lasting and provide the sealing strength you will need to stop leakages long-term.
  • Inspect your registers and vents- Are they well-connected? If not, tighten your wall vents and seal any gaps between the duct system and register connections to ensure you are not losing valuable air. Creating these tight connections where your system delivers air to your rooms will help avoid duct leakage and keep your HVAC running efficiently.
  • Insulate your ductwork- Wherever possible make sure your ductwork is insulated, especially if it’s in unconditioned areas like an attic or garage. Insulating your ductwork will reduce opportunities for air to escape your system and provide better HVAC system efficiency, saving you hundreds of dollars over the life of your system.

When do you need to call a professional?

If you have tried all of these tips and your energy bills are still higher than average, or if you don’t feel comfortable crawling through your house looking at your ductwork, use the “Find a Contractor” link on our website to connect with one of our licensed HVAC professionals.