Skip to Content

Dealing With Noisy Air Vents


With as much as you run your air conditioner in the warm South Bay Peninsula and Santa Cruz summers, noisy air vents can quickly get on your nerves. If you're tired of vent noises, there are a few things you can do.

Vents That Whine

A high-pitched whining, whistling or singing noise coming from the air vents is a common complaint. Sometimes a dirty air filter can cause this noise by obstructing airflow. Check your filter monthly and replace it when you find a layer of dust on it.

This noise also occurs when the system is getting too little return air. Many homes have only one or two return air ducts, which doesn't provide enough space for all the return air the system needs. That forces the motor to draw an excessive amount of air through the ducts, causing high air pressure. It's this fast-moving, high-pressure air that makes the noise. To stop the noise and boost your system's energy efficiency, a heating and cooling technician can install more return ducts in your home.

Undersized air ducts can also cause whistling from the vents. While replacing the ducts is more labor-intensive than installing return ducts, it can be done.

Vents That Rattle

If your noisy air vents are making rattling, tapping or flapping sounds, it's usually a sign something is stuck inside the duct and being blown around by the passing air. If you hear the noise near one vent or register, unscrew and remove the cover. With a flashlight, inspect the inside of the duct for foreign objects such as a screw, chunk of insulation or child's toy.

If you don't spot anything, contact a heating and cooling technician to perform a duct inspection. The technician will bring in a specialized video camera on a cable that can be fed through the ducts to view hard-to-reach sections. You'll also find out if your ducts have any dust buildup, mold or other contamination.

Visit our website for in-depth information on most HVAC topics, or just give us a call at (408) 868-5500.

Our goal is to help educate our customers inthe South Bay Peninsula and Santa Cruz areas of Californiaabout energy and home comfort issues (specific to HVAC systems).

Share To: