Window AC Maintenance Suggestions, How to maintain a  window AC unit

Window AC maintenance suggestions speak to how to maintain a window AC unit and window AC maintenance procedures are for single room air conditioners. Maintenance procedures will be outlined in the manufacturer's instructions that are provided with the unit.


  • Check for particulate accumulation on filters. Clean or replace if accumulation results in pressure drop or airflow outside of established operating limits.
  • Check air filter and housing integrity. Correct as needed. Quarterly
  • Check UV lamp. Clean or replace as needed.
  • Semi-annually

  • Check control system and devices for evidence of improper operation. Repair, adjust or replace components to ensure proper operation.

  • Check condensate drain path and remove debris as needed to assure it is free flowing.

  • Check for proper operation of cooling coil. Clean, restore or replace as required.

  • Check motor contactor for pitting or other signs of damage. Repair or replace as needed.

  • Check fan blades. Clean, repair or replace as needed.

  • Check refrigerant system temperatures. If outside recommended levels, find cause, repair and adjust refrigerant to achieve optimal operating levels.

  • Check integrity of all panels on equipment. Replace fasteners as needed to ensure proper integrity and fit finish of equipment.

  • Check drain pan, drain line and coil for biological growth. Clean as needed.

  • Check evaporator coil fins. Restore if possible. Replace coil if necessary to return to proper functioning.

  • Inspect for evidence of moisture carrtover beyond the drain pan from cooling coils. Make corrections or repairs as necessary.

  • Inspect air cooled condenser surfaces. Repair or clean as needed.

  • Visually inspect areas of moisture accumulation for biological growth. If present, clean or disinfect as needed.

    To properly maintain ac equipment it is suggested that the various parts of the air conditioner be understood.

    The major parts of an air conditioner manage refrigerant and move air in two directions: indoors and outside:

  • Evaporator - Receives the liquid refrigerant
  • Condenser - Facilitates heat transfer
  • Expansion valve - regulates refrigerant flow into the evaporator
  • Compressor - A pump that pressurizes refrigerant

    The cold side of an air conditioner contains the evaporator and a fan that blows air over the chilled coils and into the room. The hot side contains the compressor, condenser and another fan to vent hot air coming off the compressed refrigerant to the outdoors.

    In between the two sets of coils, there's an expansion valve. It regulates the amount of compressed liquid refrigerant moving into the evaporator. Once in the evaporator, the refrigerant experiences a pressure drop, expands and changes back into a gas.

    The compressor is actually a large electric pump that pressurizes the refrigerant gas as part of the process of turning it back into a liquid. There are some additional sensors, timers and valves, but the evaporator, compressor, condenser and expansion valve are the main components of an air conditioner.

    Although this is a conventional setup for a window air conditioner, there are a couple of variations you should know about. Window air conditioners have all these components mounted into a relatively small metal box that installs into a window opening.

    The hot air vents from the back of the unit, while the condenser coils and a fan cool and re-circulate indoor air. Bigger air conditioners work a little differently.

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