Cleaning Air-conditioning Filters

Cleaning Air-conditioning Filters

Air conditioning systems, especially in the Australian summers are a essential item for any home that is lucky to have one, but most people don’t read the instructions beyond basic operation, and the installer doesn’t inform the customer of the appropriate maintenance procedures they should be taking to get the most of their new system.

Have you noticed that;

  • Your electricity bill is larger then usual?
  • That your allergies are playing up more frequently?
  • That your air-conditioning system doesn’t seem to be cooling as quickly or as well as it used to?

If you answered YES to any of these questions then your air-conditioning filter could be dirty and may need a cleaned or replaced.

There are many benefits in making sure your aircon is properly serviced and cleaned at regular intervals, these can include health benefits, lowering the cost of your electricity bill and the prolonged life of the system itself.


One of the most important maintenance tasks that you should be doing to improve the efficiency of your air-conditioning system is to regularly clean the filters on your system. Dust build up on the filters will start to interfere with the airflow of the system causing it to not work efficiently and make the system overall work harder.

A dirty filter could cause your air-conditioning system to work up to 15% less efficient and add strain onto its compressor. This will result in less efficient cooling, higher electricity bills and decrease in the system life.

When cleaned, your air-conditioner will work more efficiently by cooling the room faster and it will keep its preset temperature more accurately

The air filter in your air-condition system should be checked at least once a month, and cleaned or changed no more then every 3 months. If the environment is dirty or has pets then we recommend cleaning it monthly to account for the extra dust and pet hair it will be catching.


The filter in your air-condition unit catches dust and dirt, but if neglected it can harbour mould and bacteria which can be sucked into the system and back out into the air of the room you are trying to cool. People with allergies and asthma may notice a increase in symptoms and attacks in rooms with air-conditioners that are not regularly serviced but may not necessary realise or attribute the cause to the air-condition system.

For the health of your family in your home, or the staff in your office you should schedule monthly filter inspections in your calendar or talk to your cleaner to add it into the cleaning contract.


There are two main types of air-conditioning units that you typically find in a home or office;

  1. Wall Unit (Standard)
  2. Central Heating

Wall units are what you typically find in most homes with a compressor outside of the house that connects to a unit on the wall on the inside. These usually have two slide out filters that are washable.

Central Air Units general found in offices will have ducting along the roof or walls, with vents at a defined distance between each other. These will usually require a ladder to access and come with washable and non-washable filters.


Cleaning a wall-unit air-conditioning filter is a simple process and it doesn’t require any special tools or chemicals.

  1. Most wall mounted units will have a faceplate that will lift up to reveal the filters. Search the front and sides of the unit for tabs or finger indents that will indicate where you should pull the faceplate. These are generally held in by a clip so a little bit of force may be required to dislodge the faceplate for the unit.
  2. Once opened you will see one or two filters that have convenient tabs to help you remove the filters. Pull the tabs and the filters should slide out of units guide rails. Take note of the orientation of the filters so you don’t put them in backwards once they’re cleaned.


    Left: Wall Unit Right: Opened Lid showing the filters

This is a good time to inspect the fins of the air-conditioning unit. The fins are located behind where you had just removed the filters. Visually inspect the fins and make sure that there are not too many that are bent or damaged. If you do find some are damage then you can purchase a fin-comb to straighten the fins out. This step isn’t extremely important but our goal is to keep the airflow of the unit as efficient as possible and bent fins will block air flow.

3. Take the filters outside and use a brush to clean the dust off the filter panels. Once you have removed as much dust off as possible take a hose or place the filters under a sink and wash the filters with soapy water. Leave outside to dry before putting them back into the air-conditioner unit.

4. Before placing them back into the unit its a good idea to brush off the faceplate of any dust and give it a wipe down. When brushing inside the unit, be careful not to bend any of the fins under the filter assembly.

5. Place the filters back into the unit making sure they are in the right direction and secured tightly. Close the faceplate and press firmly until you hear the click of the faceplate clipping back in to its spot.

6. Turn on the unit and check that everything is working correctly then you are done. Enjoy your fresh clean air.

Check the user manual that came with your unit for specific cleaning instructions for that unit


The filters in central air systems are generally located along corridors and are easily spotted by the vents or grills on the ceiling of the building. Although it may look more complicated, it is basically the same process as wall mounted units except it also has vents which can capture dust adding another layer of resistance for airflow.

  1. Firstly take a broom and brush off the vents on the ceiling. This is important as you will be opening that vent and the last thing you want to do is get a face full of dust.
  2. Once cleaned, open the vent and depending on the design you may be able to remove the vent completely or it will hang down on hinges. Brush the other side of the vent now that you have access to it to make sure the vent is completely free of dust. This will ensure proper airflow into the system.
  3. Carefully remove the filter inside the ceiling. Again, depending on the type of system you have installed, these filters may either be ones you have to replace completely, or they are able to be cleaned.


    Left: Vents of Central Systems | Right: Open vents showing filter.

If the filters are made out of mesh and metal then you can be safe knowing that they are washable. If they are just made out of fibres then you may have to replace it with a new one.

Tip: Ask your local air-conditioning specialist for re-usable filters. These may be more expensive but will save you money in the long run as they are washable and not single use.

5. Replace the new or cleaned filter back into the ceiling and close the vent and secure it into place.

6. Repeat the whole process for every vent you have in your building.

It couldn’t be simpler. 

Remember that this is only the basic level of maintenance that you are performing to your air-conditioning system and that you should at least once a year call out a professional technician to come inspect and service the rest of the system and keep it running at 100% efficiency.