Noisy Ductwork? What Does That Hissing, Roaring or Whistling Mean?

The sound of air rushing through the ductwork of your home heating and cooling system is familiar background noise in both summer and winter. When those sounds change, however, it can be a cause for concern for the condition of both ductwork and the HVAC system itself.

Here are some of the more common causes of noisy ductwork:

Noise within the ductwork can originate inside the duct system itself, within the main HVAC unit or even elsewhere within your home. Many of these causes aren’t serious, but unexpectedly noisy ductwork should always be checked to make sure the HVAC system isn’t in danger of failure.

• Hissing, roaring, and whistling: Leaks in the supply ductwork — the ducts that bring heated or cooled air from your HVAC system into your home — can produce hissing, roaring or whistling sounds as air escapes from the ducts. If your ductwork’s leaking, you can lose considerable amounts of air, energy and money, so it’s a good idea to have the duct system inspected and any leaks repaired. Hissing sounds can also occur in the refrigerant pipes if there’s a leak in that system.
• Clanking: Clanking noises can originate in an air conditioning unit’s compressor and can indicate that the compressor is about to break down.
• Rattling, tapping and clattering: Loose or detached ductwork sections can cause rattling, banging, tapping and clattering noises within the ductwork. Animals that have gotten into the ductwork can also be the source of these types of noises.
• Clicking, ticking and cracking: These types of noises are usually caused by the ductwork itself expanding and contracting as heated or cooled air flows through the system. Heat causes expansion and cool air causes contraction. If the ducts contact the house frame or other structure during this process, noises can result.

P. K. Wadsworth Heating & Cooling is one of the leading HVAC contractors in the greater Cleveland and northeast Ohio area and has been for more than 75 years. Contact us today for more information on tracking down and diagnosing problems with noisy ductwork or to schedule a duct inspection and repair appointment.