Why Are My Ducts Dripping Water?

Water dripping from your ductwork can be quite concerning at first. It doesn’t necessarily indicate a major issue with the system, but it could be a symptom of an underlying problem that needs fixing. In some instances, it may, in fact, signify something seriously wrong that needs immediate attention. Because of this, it’s best to have a professional take a look at the ductwork to determine what you need to do. Read on to learn about nine potential reasons your ducts may drip water and understand what to do.

1. Dirty Air Filters

Dirty air filters restrict airflow through ductwork. This makes the HVAC system work harder, meaning it consumes more energy and endures unnecessary wear and tear. Both of these downsides result in higher heating and cooling costs and premature replacements. Dirty air filters also complicate indoor air quality problems, which can be detrimental to those with allergies or asthma. They do this by trapping moisture in the ductwork. Over time, this moisture can turn into ice crystals, and as they melt, they can drip water through the ducts.

2. Refrigerant Leak

Refrigerant leaks can be a real hassle to deal with since they can cause the entire cooling system to quit working. They are also dangerous to your health because they can cause air poisoning. When a refrigerant leak occurs and disables the HVAC system, the home will heat up, especially in the confined areas of the ductwork, and condensation will increase. As more and more condensation builds up in the ducts, it will drip through any cracks. Refrigerant leaks frequently occur as a result of frozen evaporator coils and age-related wear and tear like corrosion and air leaks.

3. Rusted or Cracked Drip Pan

One of the most important parts of a cooling system is the drip pan. You can usually find it under the evaporator coils. It sits there to collect moisture. The more moisture it collects, though, the more likely it is to rust or crack. Rust is a major problem with metal drain pans. Plastic ones tend to crack as a result of prolonged temperature fluctuations. When drain pans corrode or crack, you’ll likely notice water dripping from your air ducts. The pan’s installation plays a large role in how well it will hold up.

4. Plumbing Leak

Your home has pipes running everywhere. When a leak happens in a pipe located above the air ducts, water will drip on the outside of them, which can then leak through cracks and air vents. Pipes can leak for a number of reasons, including corrosion, high water pressure, tree root intrusion, clogged drains and even rapid temperature changes. You can protect your pipes from all of these concerns by insulating them.

5. Clogged Condensate Drain Line

Your HVAC system’s condensate drain line absorbs moisture from the evaporator coil as it conditions and removes moisture from the air. This line connects to a drain pan. Over time, the line can clog as a result of dirt and other debris buildup. It’s especially common for a drain line to clog with mold and mildew. When it clogs, it prevents the drain pan from draining. As a result, the drain pan might overflow, leaking water into nearby ductwork and dripping through your air ducts.

6. Damaged Duct Insulation

When warmer air mixes with cooler air in damaged or improperly installed insulation, it increases moisture buildup in the ductwork. As more moisture builds up, it will leak through cracks and holes in the insulation and out of the ductwork. Rodents and insects nesting in ductwork contribute to insulation damage, as does poor ventilation.

7. Frozen Evaporator Coils

The air handler part of your cooling system has a blower component that houses an evaporator coil. This coil can freeze as a result of airflow problems caused by a damaged blower fan, refrigerant leak, clogged drain pipe or thermostat issues. Ice buildup on the coil during freezing can hinder proper refrigerant flow, resulting in dripping liquid. Water will also drip from the coil and ductwork as the ice melts.

8. Excessive Humidity

Excess humidity is extremely problematic for ductwork, particularly metal ductwork. As warm, humid air touches the cold ductwork, it reduces the amount of water vapor in the air. This results in the air condensing (turning into condensation) and settling on the ductwork. This condensation has nowhere to go but drip. Air leaks, limited airflow, temperature fluctuations and warm air from attic spaces all make humidity levels worse and increase the chances of water dripping from ducts.

9. Broken Condensate Pump

The condensate pump transfers water from the AC through a condensate line. When the pump functions as it should, it keeps water from backing up and overflowing. However, if the pump fails, the condensate drain pan will fill up, and you’ll notice water leaking from your ductwork and air vents. Many newer HVAC models have a safety switch that automatically switches the unit off if the condensate pump breaks. A broken condensate pump might be the result of a blocked drain line or a broken drain pan.

Hazards of Dripping Water

Ductwork and air vents that leak water can lead to a host of issues, like mold and mildew growth throughout your home. Even if the mold stays in one spot of the ductwork, the air traveling through the ducts will mix with the mold spores. This air can make its way into each room of your home, significantly reducing indoor air quality. Mold and mildew also introduce challenges from a structural integrity perspective by weakening the structure of the home. The dripping water can infiltrate walls, ceilings, floors and furniture, causing extensive damage. Water dripping on floors and stairs present major safety hazards by increasing the risk of slip-and-fall accidents.

What to Do

Changing the air filter when it becomes dirty is a simple way to help avoid water from leaking into your ducting. This requires checking the filter once a month. Homes with pets and high humidity levels may need to check the filter more often. You’ll also find it helpful to check the condensate drain pipe periodically. If you notice the accumulation of any sludge, contact a professional to vacuum the pipe.

You may need to insulate the ductwork, especially if you’ve never had it insulated before. This will not only minimize condensation and keep water from dripping, but it will also lead to improved comfort and lower heating and cooling costs. Moreover, it leads to less wear and tear on the HVAC system, extending its lifespan and reducing the likelihood of breakdowns.

Another key way to reduce condensation in ductwork is to take measures to control indoor humidity with whole-home humidifiers and dehumidifiers. These systems connect to the HVAC system and automate humidity regulation. An HVAC pro may also recommend upgrading the ductwork’s ventilation components, like exhaust fans, duct fittings and any vent filters.

Trust the Professionals

Integrity Heating & Cooling has more than 35 years of industry experience helping Charlotte, NC homeowners with AC repairs, heater maintenance, indoor air quality testing, UV lights, duct cleaning and more. Contact us now to schedule a ductwork inspection for your home.