How to Remove Moisture from Central Air Vents

High humidity can cause a lot of headaches for homeowners, both figuratively and literally. In homes where the humidity level rises above 60 percent, moisture can start building up around the vents. While this may not seem like a serious issue, excessive moisture can cause mold and bacteria to grow resulting in the spores being spread throughout the home every time the air conditioner kicks on.

Adjust the Humidity in the Home

Since high humidity is the cause of moisture developing in and around central air vents, adjusting the home's humidity to a lower level helps control this problem. Portable dehumidifiers in each room where condensation is found in or around the vents helps control moisture. Programmable dehumidifiers should be set to automatically turn off once the humidity level drops to between 30 and 40 percent. When the dehumidifiers are not programmable, a humidity gauge can check the level of humidity in the rooms. You also have to manually check the collection pans from time to time to prevent the collected water from overflowing.

Damp Vents and Breathing Problems

Condensation that builds up around vents and in ducts can wreak havoc on people with sensitive respiratory systems and those who suffer from asthma or severe allergies. Keeping the vents clean and dry, and keeping the home's humidity level below 60 percent goes a long way toward making the home safer for these individuals and the rest of your family.

Clean It Up

Moisture can be wiped away by hand with clean, absorbent rags as it accumulates. Turn off the air conditioning at the thermostat before wiping down the outside of the vent. The vent cover is easily removed to access the interior of the duct to remove any moisture there as well. Kill any bacteria associated with the moisture by wiping down the vent with undiluted white vinegar as you wipe away excess moisture.


There are several things you can do to help control the indoor humidity in your home besides using a dehumidifier. For instance, you should avoid shampooing your carpets on days when the outside humidity level is high as this prolongs the carpet's drying time and can add more moisture to the indoor atmosphere. You should also use the bathroom exhaust fan when showering and make sure your windows and doors are properly sealed. Insulating cold air supply ducts and wrapping your cold water plumbing pipes also helps reduce the amount of moisture throughout the home.