Room air conditioners can make noise while operating. Below are the most common noises or sounds:

Air Flow


  • An air conditioner must circulate indoor air to heat/cool the occupied space. Therefore, air noise will be heard when the fan is operating.
  • The compressor also makes a noise while operating. 
  • When the energy selector is in the cool or fan position, the fan will run continuously. This is normal operation.

Thermostat Click


  • When the compressor cycles on and off a metallic sound may be heard. This is considered normal.

Water Dripping Outside


  • Air conditioners must be installed so that they are slightly tilted to the outside. On hot and humid days the air conditioner drip excess water on the outdoor side of the unit. This is considered normal operation.

Rattling or Vibration


  • If the front grille is loose or the moveable air directional louvers are loose or broken, they can make a rattling sound. 
  • Improper installation may cause a vibration in window sill. Check that the side panels are properly fastened.