Leaky AC ductwork can lead to the escape of heated air from your indoor spaces during winter or chilled air during summer, making your home uncomfortable and increasing your utility bills. Here is a look at how you can locate leaks or ineffective insulation in your HVAC ductwork and repair the damage so as to improve the efficiency of your heating and air conditioning.
Finding leaks or damaged insulation
Poorly sealed ducts will not only allow conditioned air to escape to the outdoor, but can also cause excess moisture in spaces such as the attic and crawlspace, leading to a mold infestation. To check for leaks, run your hand along the ducts in your crawlspace while the AC is on so as to feel any escaping air. Pay particular attention to joints in the ducts or areas where runs of ducts meet. To find hidden leaks, call in an HVAC specialist to run a pressurized test on the entire AC system.
Next, check for discoloration of the insulation which could indicate a poorly sealed duct. Condensation along the ducts in your crawlspace may also indicate a poorly insulated pipe during summer when humidity levels are high.
Repairing leaky or poorly insulated ducts
Once you locate any damage in the ductwork, mark the affected sections with chalk and then turn off the HVAC system so as to stop air flow through the pipes. Next, place a layer of metallic foil tape to cover any holes or cracks in the ducts. This type of tape is designed for sealing ductwork and can usually hold up to extreme temperatures, preventing any further leaks. You can then cover the metallic foil tape with duct mastic tape to hold it tightly in place and add a layer of insulation to the ductwork.
For areas with damaged insulation, a fresh layer of foil faced fiberglass insulation could be used to seal the AC piping. To achieve a snug fit that won't compress the fiberglass against the duct, use a sharp knife to cut the insulation to width and length and then wrap it gently around the poorly sealed area. Use long strips of dust mastic tape to hold the seam of the insulation in place and entirely wrap sections where old and new insulation join together with large strips of mastic tape.
For AC ductwork that is excessively leaky, or where the insulation has been seriously degraded, calling in an HVAC specialist like Reed Heating to repair and insulate the entire ductwork could be more feasible so as to get the system efficient.