An unusual sound from any of your heating and cooling system’s components can understandably raise your concerns. It can disturb your focus, be highly irritating, and may require you to call a service technician. However, if your fan is the culprit, you may find that the solution is usually a simple repair. So, what could be causing that sound?
The first step you should take when you notice a sound coming from your HVAC system’s fan is to check your filter. A dirty or clogged air filter is a common cause of fan noise and is simple to replace. Every type of filter needs to be changed periodically. Check the packaging of the filter or call your HVAC technician to ensure that you have been changing it frequently enough to keep your indoor air clean. Changing your filter regularly is essential for optimal indoor air quality as well as enhancing your HVAC unit’s efficiency. If you look at your filter, and it’s grey, it’s time to swap it out for a new one. If the filter is dark brown or black, call a professional.
Many air filters only need to be changed every three months. However, if you have a higher quality filter or health concerns, you may need to change your filter more frequently. If the filter needs to be changed filter more often than recommended by the manufacturer, there may be another issue, such as dirty ductwork. Please consult a professional to diagnose the problem.
When the air filter has not been changed on a regular basis, it can clog up your system and restrict airflow, causing the fan to work harder. This increased workload can result in a noisier fan. The sound of your heating, ventilation, and air conditioning system’s fan should be barely noticeable.
Other HVAC Fan Noise Causes
- Worn Motor Bearings: If you hear a hum or buzz when the system starts up or shuts down, the motor bearings on the fan have probably worn down over time. You will need to either have them lubricated or replaced.
- Loose or Damaged Fan Blades: If the fan blades in your HVAC system are loose or damaged, they can cause the fan to wobble or vibrate. Loose or damaged blades can cause a bumbling sound or, in extreme cases, a thumping noise when they bang against the side of the unit. Call an HVAC technician to get the blades tightened or replaced.
- Blower Motor Issues: The blower motor in your HVAC system is responsible for moving air through the ductwork. Common problems with blower motors include worn or damaged belts or loose/damaged pulleys. These issues can make various sounds and should be addressed swiftly.
- Improperly Installed Ductwork: If the ductwork in your HVAC system is not properly installed, air will flow unevenly through the ducts, and this can cause many different noises. If ductwork is the cause, the sound will be amplified in the ducts near the fan. You may need to have your ductwork repaired or reinstalled.
As you can see, there are a variety of issues that can cause a loud HVAC fan. If you are experiencing this problem, having the system inspected by a certified HVAC technician is essential. They can determine the cause and recommend the best course of action to fix it. Don’t hesitate to seek professional help, as a noisy HVAC system can lead to decreased comfort, higher energy bills, and more repairs if left unaddressed.
If you’re looking for one-on-one expert advice about your HVAC options in New England, contact the National Refrigeration team, and we’ll find the right solution for you.
Whether you need 24-7 emergency service or advice on improving your everyday air quality and comfort—at home and work—call us at 401-737-2000 or email us.
