How To Stop Condensation On Air Ducts

How To Stop Condensation On Air Ducts

When the sweltering summers roll around, it’s no secret that your air conditioning unit is forced to work its hardest to keep your home comfortably cool. As a result, you may have noticed the formation of water droplets on visible air ducts and are a tad curious as to whether that’s normal.

If you’re wondering how to stop condensation on air ducts, you need to first determine what is causing the condensation, so you can determine what kind of repairs, if any, are needed to remedy the situation.

Read on to find out more about how to stop condensation on air ducts.

What Triggers Condensation On Air Ducts?

What you see is condensation that most people refer to as ductwork sweating. While it doesn’t always imply that your AC unit is susceptible to damage, condensation is still something that calls for your attention.

For starters, any amount of moisture in your home is an excellent breeding ground for mold. Likewise, condensation on your ductwork might be a marker of a bigger problem.

As the humidity level increases outside, condensation will slowly start to form on the surface of the ducts. The colder the air inside the duct is, the higher the likelihood of ductwork sweating.

As a natural process, it’s similar to how a cold beverage starts sweating once you remove it from the refrigerator on a hot day. That occurs because the cold air cannot retain as much moisture as warm air.

Once the moisture-filled, warm air comes into contact with the cold glass, it’s forced into the air to condense into countless water droplets that form on the surface of the glass. Nonetheless, the following factors exacerbate or trigger ductwork sweating:

  • Dirty air filters
  • Poor insulation
  • Blocked ducts
  • Excessive moisture in the atmosphere

At times, duct condensation can be the marker of a duct leaking air, reducing the efficiency of your AC unit. If ductwork isn’t well-maintained or you live in an older home, condensation on air ducts is more likely to become an issue with soaring humidity levels and temperatures.

When Should You Be Concerned About Condensation On Air Ducts?

Although occasional duct condensation is a non-issue, keeping your eyes peeled on the situation is wise. Continuous ductwork sweating might eventually cause water damage.

Excessive condensation can trigger conditions for mildew or mold to thrive, forming around the ducts. In addition, anyone susceptible to developing allergies or suffering an asthma attack might experience more adverse symptoms if mildew and mold develop and spread to other areas of your home.

What Can You Do About Condensation On Air Ducts?

Choose insulated materials like flexible fiberglass rather than metal to prevent duct condensation that results in leaking. If you have metal ducts, ensure they are well-wrapped with fiberglass insulation.

Although a great fit is required, tightly-wrapped insulation will be less effective at diminishing ductwork sweating. Alternatively, you can follow the steps below to stop condensation on air ducts:

  1. Reduce the level of humidity around the ducts. Keep them well-spaced to allow sufficient air circulation between them. If the ducts are situated in a crawlspace underground, cover the soil to diminish moisture. If they are tucked away in your attic, ensure the area is well-insulated and that any holes or cracks are tightly sealed. If you reside in a consistently humid climate, a dehumidifier is your go-to to keep the air around the ducts dry.
  • Unblock the ducts that constrict airflow and ensure frequent cleaning. When air can’t circulate freely throughout your AC unit, the interiors of particular ducts will become colder, increasing the chances of ductwork condensation.
  • Make sure the air filters are spick and span and replace them frequently. Filter replacements every three months are advisable. However, you can follow the instructions that come with the air filter you buy. If you’re a pet owner or one of the members of your household is allergic to dust, more frequent filter replacements are necessary.
  • Ensure leaking ducts are fixed. The more cold air seeps out, the greater the level of condensation. You can use a pressure gauge or simply place your hand on the duct to feel for air escaping, to notice leaking ducts.

How Can You Tell Whether The AC Unit Requires Repair?

If you notice any of the following, then it’s time to rope in an HVAC expert to diagnose the root cause of ductwork condensation:

  • Reduced airflow can be the marker that your AC compressor is no longer functioning as it should. If filter replacements don’t rectify the problem, then the compressor may require attention
  • A rattling AC unit could mean the presence of a broken fan in the unit
  • An immediate condensation increase on the outer surface of the AC system could indicate a pressure leak or a problem with the internal temperature
  • Irregular temperatures in your home, for instance, warm and cold zones on the same floor or room, could mean an issue with the air ducts or AC unit entirely
  • Pungent smells through your air vents might indicate that the AC system requires professional maintenance and cleaning, particularly if you don’t replace the filter as frequently as you should
  • A spike in the power bill compared to previous months or years, particularly during the summer, might also be a tell-tale sign that your AC system is finding it a challenge to keep your home cool. That could be the case even though air duct condensation and leaking are not easily noticeable yet. In this scenario, an energy audit coupled with a professional inspection will help you determine the level of efficiency of the AC unit

Other Dangers Of Condensation On Air Ducts

Granted, the small droplets of water that accumulate on air ducts are harmless. However, if your vents sweat immensely, it can elevate the humidity levels in your attic. Besides the hot, humid environment that provides excellent conditions for mold and mildew to grow on the insulation and drywall, it’s worth noting that these droplets pose other dangers.

If the droplets are rolling off your cold ducts and your refrigerant levels are low, there’s the likelihood of your vents freezing over. Ducts loaded with ice become heavier over time until they may eventually fall through your attic, causing immense damage, and that’s the last thing you need.

To avoid resigning to this fate, it’s always a great idea to closely monitor the duct system in addition to frequently condensing the drip pan. Once you notice an excessive amount of water on the ductwork and drip pan, you’ll need to have a licensed professional conduct a thorough assessment.

While you may not realize it, vapor barriers aid in keeping moisture out of the space; therefore, installing these in your attic can save you thousands of dollars worth of repairs and damages. They’ll diminish humid air from seeping into the attic and minimize the condensation on your ductwork.


Armed with this profound knowledge, you now know how to stop condensation on air ducts and the repercussions. Although these DIY tips can be a lifesaver, it wouldn’t hurt to contact an expert when you’re having an issue with water damage from your AC unit. If you need assistance in an AC unit replacement or repairs, a home warranty is your friend.