Cleaning your air conditioner is a task many overlook, yet it’s crucial for maintaining indoor air quality and ensuring your system runs efficiently. Not only can a clean air conditioner prevent the buildup of dust and mold, which degrades the air inside your home, but it can also save you money by running more efficiently. This guide focuses primarily on cleaning split-system air conditioners, a common type in many homes, but the principles can also apply to ducted and wall-window units. Whether you’re a seasoned DIY enthusiast or new to home maintenance, our step-by-step approach will make the cleaning process straightforward and effective.

clean your air conditioner

Look at the manual

Your air conditioner comes with a manual that explains how to reach and clean the air filters and other parts you can maintain. If you’ve lost the manual, you might find a copy on the manufacturer’s website.

Cleaning the filters and louvres of your air conditioner

Clean the indoor unit’s dust filters

The indoor unit of your air conditioner has dust filters that should be cleaned regularly. If the filter is very dirty, the air conditioner will have to work harder to push air through, which could lead to increased operating costs.

Cleaning it is typically easy. Just open the plastic cover and take out the filter (there might be more than one). Use a small stepladder if the indoor unit is too high to reach easily.

Manufacturers often suggest cleaning the dust filters every few weeks, but it really depends on how much you use your air conditioner. The more you use it, the more frequently you should clean the filters. At a minimum, try to clean them a few times a year. For instance, if you mainly use your air conditioner in the summer, clean the filters in the spring to prepare for the busy season, and again after summer ends.

  • Take the dust filters outside and either brush them off or give them a good shake. You can also vacuum them for a deeper clean—use the dusting brush attachment of your vacuum cleaner if you have one.
  • If the dust filters are really dirty and grimy, you can wash them in warm, soapy water, then rinse them thoroughly. Ensure they’re fully dry before you put them back into the air conditioner.
  • If the filters are damaged, it’s time to get new ones. Look in the manual or on the manufacturer’s website to find out where to buy replacements.

Some air conditioners come with an air purification filter, like an ionizing filter, which you can take out and clean. This kind of filter will need to be replaced eventually, maybe every year or two, based on how much you use it. Make sure to check the instructions for details on how to clean or replace this filter.

To clean the louvres of your air conditioner:

You might be able to take off the louvres (these are the blades that move to direct airflow) from the indoor unit. Clean them and the area behind them in the unit using a dry cloth or a vacuum cleaner. Remember to turn off the power to the air conditioner unit before starting this cleaning.

In areas with a lot of dust or humidity:

Living in a very dusty or humid place and using your air conditioner a lot can lead to a surprising amount of dust and mould building up inside the unit. This can cause the air conditioner to lose efficiency as it gets clogged, and it might also spread mould spores into your home. Additionally, if the indoor unit’s drainage pipe is blocked by debris, it could lead to water leaks.

To prevent these issues, regularly clean the dust filters and louvres. Using the air conditioner in fan-only mode, or running a ‘dry out’ program if your unit has one, can help keep the inside of the indoor unit dry. However, getting a professional to service and clean your air conditioner occasionally is also a good idea.

Cleaning the outdoor unit of your air conditioner

Make sure the outdoor compressor unit is free from grass and plants around it, and regularly remove dust, leaves, and cobwebs.

Using a vacuum cleaner on the air intake can help remove dust from inside.

It’s not advised to open the unit to clean its internal parts yourself. It’s better to have a professional service handle that.

Having your air conditioner serviced and cleaned by a professional

It’s important to have your air conditioning system serviced by a professional on a regular basis. During a service, the technician will check the levels of refrigerant gas, test the thermostat, and ensure all internal components are in good working order. Regular servicing can extend the lifespan of your unit.

Recommendations on service frequency vary among manufacturers. Some suggest an annual service, while others state that following the user manual for regular cleaning of filters and units might be enough, advising professional service only if the unit malfunctions.

A survey of Home & Cleaning members revealed that many clean their air conditioner filters several times a year but generally only seek professional servicing every few years or when a problem occurs. If you’re unsure, consult your air conditioner’s manual or contact the manufacturer for their recommended servicing guidelines.

Getting your air conditioner professionally cleaned

Opting for a professional cleaning service for your air conditioner includes thorough cleaning of its internal parts like coils, fins, and drainage system. This is particularly advisable if you’re in a location with a lot of dust or humidity, as these conditions can lead to significant accumulation of dust and mould inside your unit, potentially affecting its performance and the quality of air in your home.

Air Conditioner Cleaning Cheat Sheet

Monthly Tips

  • If you often use your air conditioner, occasionally switch it to fan-only mode. This helps dry out any moisture inside the indoor unit, which can prevent mould and bad smells.

Bi-Annually

  • Clean the dust filter screens in the indoor unit of your split-system air conditioner, or follow the specific cleaning instructions for your ducted system. Increase the frequency of cleaning if you’re constantly using your air conditioner, live in a very dusty area, or notice a decrease in its performance.
  • Clean any additional filters, like air purifying filters, according to the guidelines provided.
  • Use a soft, damp cloth to gently clean the inside (as far as is safely possible) and the exterior of the indoor unit, as well as any ducts or vents.

Annually

  • Use a soft brush or broom to clean the outdoor unit. Make sure to clear away any plants, blockages, spider webs, etc., as needed.