How to Clean Your Air Conditioner Filters

Regular cleaning can help maintain airflow, efficiency and indoor air quality
General maintenance guidance for split-system, ducted and wall-window air conditioners
Air-conditioner filters are designed to capture dust and, depending on the filter type, may also trap other airborne contaminants. If filters are not cleaned regularly, airflow can reduce and the air conditioner may need to work harder to cool or heat the room.

1. Why Cleaning the Filters Matters

Air-conditioner filters need regular cleaning to help maintain good airflow and system performance.

As filters collect dust, they can become clogged. This can:

  • Reduce airflow through the indoor unit.
  • Make the air conditioner work harder.
  • Increase running costs.
  • Reduce cooling or heating performance.
  • Allow moisture and dirt to build up if maintenance is neglected.
General rule: The more often the air conditioner is used, the more often the filters should be checked and cleaned.

2. Check the Operating Manual First

Before removing or cleaning filters, refer to the operating manual for the specific air-conditioner model.

The manual should explain:

  • How to access the filters.
  • Which filters are washable.
  • Whether additional air-purification filters are fitted.
  • How often cleaning or replacement is recommended.
  • Any model-specific precautions.
Important: Not all filters are cleaned in the same way. Always follow the instructions for the specific model and filter type.

3. Cleaning the Indoor Unit Dust Filters

Most indoor units have one or more removable dust filters positioned behind the front cover or intake grille.

1Turn the air conditioner OFF before cleaning.
2Open the front cover or intake grille in accordance with the operating manual.
3Carefully remove the dust filters.
4Take the filters outside and gently brush, shake or vacuum away loose dust.
5If the filters are washable and heavily soiled, wash them using warm water and mild detergent, then rinse thoroughly.
6Allow the filters to dry completely before reinstalling them.
7Reinstall the filters and close the cover correctly.

How Often Should Filters Be Cleaned?

Cleaning frequency depends on how often the system is used and the environment in which it operates.

Frequent useCheck and clean filters more regularly.
Seasonal useClean before the main operating season and again after heavy seasonal use.
Dusty environmentInspect filters more frequently because they may clog faster.
Replace damaged filters: If a filter is torn, cracked, distorted or otherwise damaged, it should be replaced with the correct part for the air conditioner.

Air Purification Filters

Some models also use additional air-purification filters, such as deodorising, ionising or antibacterial filters.

These filters may have different cleaning and replacement requirements from the main dust filters. Refer to the operating manual before washing, vacuuming or replacing them.

4. Cleaning the Indoor Unit Louvres

The louvres are the moving blades that direct the discharged air.

Where the model allows user cleaning:

  • Turn the air conditioner off.
  • Wipe accessible louvres with a soft, dry cloth.
  • Use a vacuum cleaner carefully to remove loose dust where appropriate.
  • Do not force or bend the louvres.
  • Do not remove parts unless the operating manual specifically permits it.

5. Dusty or Humid Environments

Air conditioners operating in dusty or humid environments may require more frequent cleaning.

Dust, moisture and dirt can build up inside the indoor unit and may contribute to:

  • Reduced airflow.
  • Reduced cooling or heating performance.
  • Unpleasant odours.
  • Mould growth.
  • Drainage problems or water leakage if the drain becomes restricted.
Regular filter and louvre cleaning can help reduce build-up. On applicable models, running fan-only mode or a dedicated drying function can also help dry the inside of the indoor unit after operation.

6. Cleaning Around the Outdoor Unit

The area around the outdoor unit should be kept clear so air can move freely through the heat exchanger.

  • Remove leaves, grass and other loose debris around the unit.
  • Remove cobwebs and surface dust where safely accessible.
  • Keep plants and vegetation from obstructing the air intake or discharge.
  • Do not place objects directly against the outdoor unit.
Do not open the outdoor unit: Internal cleaning and servicing should be carried out by an appropriately qualified air-conditioning technician.

7. Professional Cleaning and Servicing

Routine filter cleaning can be carried out by the user where permitted by the operating manual, but internal maintenance requires professional attention.

A professional clean or service may include inspection and cleaning of:

  • Indoor heat exchanger coils.
  • Fan and blower components.
  • Drainage system.
  • Outdoor heat exchanger.
  • Electrical components.
  • Overall system operation.

Professional cleaning may be particularly worthwhile where the air conditioner operates in a very dusty, humid or high-use environment.

Service intervals: Requirements vary between models and installations. Refer to the applicable operating manual and arrange professional service where required or where a fault, unusual noise, odour, water leak or loss of performance is present.

8. Quick Reference

ItemRecommended Action
Dust filtersBrush, vacuum or wash if permitted by the operating manual.
Dirty washable filtersWash with warm water and mild detergent, rinse and dry completely.
Damaged filtersReplace with the correct filter.
Air-purification filtersFollow model-specific cleaning and replacement instructions.
Indoor louvresClean accessible surfaces carefully with the unit off.
Outdoor unit surroundsKeep clear of grass, plants, leaves, dust and debris.
Internal componentsArrange professional cleaning or servicing.
Safety: Turn the air conditioner off before carrying out user maintenance. Do not dismantle electrical covers or access internal electrical, refrigerant or mechanical components.