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How to Troubleshoot a Forced-Air Distribution System

Noise Problems and Heat Loss

Forced-air distribution systems sometimes are noisy or have heat loss problems. Solve these common problems using the tips listed below.

Noise Problems

Air forced through the ducts of a forced-air system can cause vibration and noise if the ducts are not firmly connected. The best way to stop this noise is to add duct hangers to the ducting system. The hangers are usually wrapped around or across the ducting and nailed or screwed to the stud or rafter framing.


At the elbows of the ducts, where air moving through the ducts changes direction, the duct sections can become loose or separated. Push loose sections back together, and tape the joints firmly with duct tape to stop vibrations.

Noise can also be caused by inadequate lubrication, worn or damaged belts, or too high blower speed.

Heat Loss From Ducts

If ducts run through cold basements or exterior crawl spaces, wrap the ducts with fiberglass insulation. Spiral insulation around the ducting and secure it with duct tape, wire, or heavy cord. Or, wrap the ducts with aluminum-face insulating tape, sold in wide rolls and available at heating supply stores.

When a forced-air system malfunctions, it can seem like a daunting challenge. But the tips mentioned in this article will help you solve the crisis yourself.

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