How to Deal with Moisture Around A/C Vents

When you see signs of moisture around your HVAC vents, whether in the form of water stains or condensation, the problem should be addressed immediately so that damage doesn’t worsen. There could be any one of several reasons why the vent moisture is occurring, and you may need a professional opinion to help you figure it out.

What Causes Vent Moisture?

Vent moisture is common in humid areas such as ours. It’s usually due to condensation forming on ducts and leaking onto the ceiling. The condensation occurs when cold air from the vents mixes with the warm, moist air in your attic. The condensation on ductwork can drip down into the ceiling and create water stains or even set up conditions for mold growth. Dripping condensation may also get on your insulation and decrease its effectiveness.

Generally, the reasons for this are as follows:

• Air leak
• Inadequate duct insulation
• Vent “boot” needs more insulation

While these are the most common causes of vent moisture, it pays to have an HVAC professional assess the situation, just in case something else is going on.

Fixing the Problem

Some homeowners are capable of repairing cracked or separated ductwork, or even adding insulation around ducts. However, if your ducts are not easily accessible and you have no experience repairing air leaks or adding insulation, you may want to hire a professional.

Sometimes air leaks occur when the vent boot becomes separated from the duct, or the vent becomes separated from the dry wall. The repair usually involves sealing the leak and adding insulation around the vent boot.

You might also need to improve ventilation in your attic. In our climate, hot, humid conditions are magnified in the attic so it’s important to have your attic assessed to ensure it has enough roof ventilation.

Another fix could be adding a vapor barrier to the ductwork. Most modern ductwork comes equipped with insulation and a vapor barrier, but if yours lacks it, hire a pro to add it.

For more on vent moisture, call CCAC. You can also schedule maintenance, repairs and new equipment installations.

Our goal is to help educate our customers in Corpus Christi, Texas about energy and home comfort issues (specific to HVAC systems). For more information about your HVAC system, download our free Home Comfort Guide or call us at 361-678-2495.