Ducts are thin sheet metal tubes that transport air from a central HVAC system to vents in a home's rooms. Occasionally, they can make unusual sounds, indicating underlying issues an HVAC contractor may need to address. If you're experiencing noisy ductwork, here are a few possible reasons the problem has developed.

4 Causes of Unusual Duct Sounds

1. Leaks

When the HVAC system starts to cycle, you can notice the sound of ductwork expanding, accompanied by a dull roar. This behavior is normal and occurs due to pressurized air moving through the tubes. However, hearing hissing or whistling can indicate air leaking through holes or tears.

These openings often form due to repeated expansion and contraction over time. An HVAC contractor can replace the damaged segments to restore quiet operation and prevent the loss of heated or cooled air.

2. Closed Vents

When vents are closed, air pressure can build up behind them while the HVAC unit runs, producing loud rumbling sounds. In addition to causing disturbances, the system will work harder and use excess power to push air through closed vents. This leads to energy waste and elevated utility expenses. Opening the vents reduces air pressure, stops noise, and enhances efficiency. 

3. Debris Buildups 

Dirt, dust, and pet dander typically collect inside the ductwork over time. As air blows through the metal tubes, it lifts and scatters debris, causing popping or crackling sounds. 

Since dirty HVAC filters typically cause more contaminants to enter the ducts, changing them at least once every month will keep the tubes clean and reduce noise. This measure also prevents dirt, dust, and other particulate matter from blowing out of the vents and settling onto interior surfaces.

4. Poor Installation

Ducts are typically installed behind walls or above ceiling tiles. Without leaving enough space between the metal tubes and the home's framework, the conduits can shift and rub against surrounding building materials, producing scraping or scratching sounds. An HVAC contractor can reinstall the ductwork correctly to stop the noise and prevent structural damage to your property.

If you ever notice unusual ductwork sounds, turn to Parker's Heating & Cooling for a solution. Their North American Technician Excellence-certified contractors provide clients throughout Cairo, GA, with duct repairs and replacements, as well as cooling and heating system services. Call (229) 377-9129 to book an appointment, and visit the website to learn more about how they can keep your unit serviceable.