Can You Quiet Outside Air Conditioner Units?

Debris

• Sometimes, debris such as sticks or a plastic bag can get sucked into the unit through the intake grille. The trash can lodge itself in or around the condenser fan motor, causing the fan to bind up and not blow effectively. If you suspect the presence of debris inside the unit, you should first turn the air conditioner’s circuit breaker off. The fan-housing panel on the outside unit can then be removed to reveal the fan. If you see any debris, remove it from the unit and replace the fan-housing panel.

Ball Bearings

• Properly lubricated ball bearings are required for smooth operation of the condenser fan. If the ball bearings become dry or dirty, the fan has a hard time turning, which can create quite a ruckus. You can turn off the circuit breaker and remove the fan-housing panel to test the ball bearings. The fan blades should spin around freely without sound. If you feel tension in the fan, the ball bearings could benefit from lubrication. You can pour electrical motor oil into the lubrication ports at the base of the air conditioner axle and spin the blades around to work the oil in.

Fan Housing

• A clanging or scraping noise is most likely due to an improperly installed or displaced condenser fan, as the fan blades rap against the fan housing when not straight. You can check the fan after the power is turned off and the fan-housing panel is removed from the main unit. Take the fan blades with your hands and spin them around. If you see that the fan blades strike the sides of the fan housing, the fan is improperly installed. You can uninstall and reinstall the fan and test the blades to confirm that they no longer hit the sides of the fan housing.

Ductwork

• Obnoxious banging caused by the air conditioner system could indicate that the ductwork inside the home is improperly secured. Ductwork expands and contracts during use, which can cause a number of noises, including vibrations. You can secure the ducts to support beams or the wall inside the attic or crawlspace with duct tape to control the noise.