How to Check Your Ductwork for Air Leaks

Your air conditioner’s ductwork is an extremely important component that affects the performance of your system. Aside from the indoor and outdoor system, the ductwork system is one of the first places to look for AC issues. Signs that your air ducts are leaking include uneven heating and cooling, a dusty home and high utility bills. Here is a step-by-step guide to check your ductwork system for leaks.

Step 1: Look for Tears

The first and most obvious step is to check your entire ductwork for holes and tears. If you spot a tear in the ductwork, mark it so you can go back later to patch it up.

Step 2: Turn Your AC on High

By turning your AC up, you make it easier to spot holes and faults in your ductwork. Air duct leaks will be more obvious when the air comes through at a high speed because it’s easier to feel and hear it.

Step 3: Inspect Duct Joints

Joints in your duct system are a common place for air leaks. It is a good idea to place your hand over these areas to make sure that no air flows through these spaces.

Step 4: Search For Old Duct Tape

Many people believe that duct tape is a good patch to a leaky air duct system, but that is not the case. Patching a vent hole with duct tape is a temporary solution to a problem that eventually needs a professional fix. Inspect your duct system to find any old duct tape that needs to be removed and sealed correctly. Mark any leaks during this process so you can patch them up later.

Step 5: Smoke Test

Anything that releases smoke can be a great tool for finding holes in your ducts. A smoke pencil or incense is a great example of a tool that you can use to perform a smoke test to find air duct leaks. Try running the tool under the ductwork system slowly, and the smoke will indicate small leaks that your eye may not catch. If you see the smoke move or twirl unusually, then you know that the smoke is being sucked up or blown off by the air duct. Mark these smaller leaks so you can patch them up later.

Step 6: Seal Up Leaks

Before you can locate any other remaining leaks, you must first seal all of the current leaks that you have marked. To seal these tears in your ductwork you must use foil-faced tape to wrap the air duct or apply mastic to the leak directly.

Step 7: Fog Machine Test

Last but not least, you can rent out a fog machine from a nearby shop and try this fog test to locate any remaining leaks. Since you already sealed up all of the visible leaks, this step will be much easier to do and will help you pinpoint an exact leak location.

By not sealing all of the previous leaks that you have found, you would make this step much harder since the fog can come out of several holes. That makes it difficult to locate where the smoke is coming through.

To perform the test, you must place the fog machine by your furnace or blower intake fan. Then, you will wait for the fog to come out of your air ducts to point out any remaining leaks. Lastly, seal up any remaining leaks that you find with foil-faced tape or mastic.

Step 8: Contact a Professional

Will the steps above guarantee a perfect air duct system? Realistically, it is impossible to ensure that you will not have issues with your system – even after completing the steps above. Sometimes it is extremely difficult to locate your ductwork system in the first place. Other times your air duct damage is so severe that you may need your ductwork replaced entirely.

The best advice that we can give you is to call an HVAC expert when your AC system is in dire need of a professional fix. For more information on air duct repair or air duct replacement, contact My Guy Heating and Air.