How To Reduce Your Air Conditioner's Excessive Operating Noise

In preparation for the upcoming spring and summer seasons, you decided to power up your central air conditioner and test its ability to cool your home. However, upon activation, you noticed your air conditioner unit began producing excessive noise. Instead of replacing your unit, reduce its noise production by performing these tasks:

Clean and Adjust Your Fan Wheel

The blower assembly that creates the airflow throughout your air conditioner system is designed as a centrifugal fan. Centrifugal fans operate by spinning a fan wheel with several blades. As the blades of the wheel spin, air is pulled into your system. However, after hundreds of hours of use, your fan wheel can become loose and scrape against the sides of your blower assembly—which will create a constant high-pitched noise while your unit is active.

To adjust your fan wheel, you'll need to remove your blower from its compartment. Shut off the power to your HVAC system and disconnect the electrical clips or wire nuts leading from your blower motor to your system. Use a ratchet to remove the bolts securing your blower to its mounting hardware. Pull your blower out of your unit's housing and set it in your yard.

Use your ratchet to remove the deflector plate covering your fan wheel. With the deflector plate removed, you'll gain vision of your fan wheel. If your fan wheel's blades are covered with debris, then take this opportunity to blast the debris out of your wheel with an air compressor or gas duster. Once the debris is removed, you can loosen the hub nut on the shaft passing through the center of your fan wheel. Guide your fan wheel into the center of your blower assembly to prevent it from making contact with the sides of your assembly.

Once your wheel is positioned correctly, tighten down your hub nut and reinstall your deflector plate. Reinstall your blower back into your unit's housing and test your work.

Clean Your Evaporator Coil

Your air conditioner cools the air in your home by blowing it through your evaporator coil. As the air flowing through your air conditioner system passes through your evaporator coil, the freezing refrigerant passing through the lines in your coil will drastically reduce the air's temperature.

Your evaporator coil can freeze during periods of extended operation while it's dirty. To determine whether or not your coil is dirty, remove the access panel on your indoor unit and visually inspect the fins on your coil. If they're covered in debris, then your coil needs to be cleaned.

To clean your evaporator coil, use an air compressor or gas duster to blast away the surface debris from your coil fins. Place a vacuum hose inside your evaporator coil's housing to prevent the debris from becoming caught on your fins once again.

Once the surface debris is removed from your coil, apply a thick layer of foaming coil cleaner to your coil (available at your local home improvement store) and activate your air conditioner. As refrigerant begins pumping through your coil, condensation will begin washing away the foam cleaner.

However, some cleaners can damage your coil if they're left in place. Read the directions on your cleaner to determine whether or not you must manually wash the foam away from your coil.

If you have to manually wash your foam cleaner off your coil, then fill a spray bottle with water and spray the water into each section of your fins. By doing so, you'll quickly cleanse all foam from your coil and prevent your cleaner from causing corrosion damage.

If you have trouble cleaning your fan wheel or evaporator coil, or if your air conditioner continues to create excessive noise while active, then give your local HVAC technician a call. Your technician, like one from Aggressive Mechanical Contractors, will be able to perform the necessary repairs that will allow your unit to operate quietly and efficiently throughout the upcoming seasons.