It’s completely normal for your central air system to make noise. The outdoor unit is going to hum and whir from the powerful fan and compressor. You may even hear swooshing sounds from refrigerant circulating through the indoor air handler. Though, if noisy air vents have reached levels that disturb your normal activities, use these tips to get to the root of the problem.

Noisy Supply Air Vents

• Whooshing — Airflow exiting the supply vents can make quite loud whooshing noises if the supply air ducts are too narrow, the ducts are caked with debris and/or one or more vents are closed. Make sure all air vents are open. Use a flashlight to look inside the vents to check for excessive dirt. If the noise persists, contact your HVAC provider for a duct inspection.
• Flapping — If duct joints separate or loosen, the adjoined metal duct sections will rattle, flap and clamor. Wrap loose or disjointed duct sections with metal tape.
• Popping — If your ducts are installed outside your home’s insulation barrier, the ducts are susceptible to extreme differences in temperature inside and out. This causes duct metal walls to expand and contract, which causes loud popping sounds. Installing rigid foam duct insulation is the best remedy in this case — and you’ll save energy!

Noisy Return Air Vents

• Knocking — Loud and rapid knocking or thumping noises indicate a very clogged filter that is obstructing return air duct. Another sign associated with this problem is rapid on-and-off cycling. Be sure to check your air filter each month during peak HVAC usage.
• Whistling — A dirty or clogged filter may also cause a high-pitched whistling sound. Check your air filter!
• Booming — The most extreme temperature variances in the air ducts tend to be at the plenum and duct trunk connection. This can cause a loud boom noises from the expansion and contraction. Your HVAC provider should check the integrity of the expansion collar joint.

If you have questions about noisy air vents in your Peachtree City-area home, please contact the HVAC experts at Powers Heating & Air today!

Our goal is to help educate our customers in Peachtree City, Georgia and surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about noisy air vents and other HVAC topics, download our free Home Comfort Guide or call us at 770-487-2040.

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