How to clean air conditioning filters
Cleaning Your Air Conditioning Filters - a simple guide.
Keeping your air conditioning filters clean is one of the simplest things you can do to help your system work properly.
Over time, filters collect dust and airborne particles. If they become heavily clogged, airflow can be reduced and the system may have to work harder to heat or cool the room.
For many domestic wall-mounted air conditioning systems, basic filter cleaning can be carried out safely by the user.
Here is how to do it.
Why do air conditioning filters need cleaning?
The filters inside your indoor air conditioning unit help capture dust and debris before air passes through the system.
As that material accumulates, the filter can become restricted.
A dirty filter may contribute to:
- Reduced airflow
- Poorer cooling or heating performance
- Increased energy use
- Unpleasant smells
- Increased dust inside the unit
- Additional strain on the system
Regular cleaning helps keep air moving freely through the unit.
How often should you clean your filters?
There is no single schedule that suits every property.
How often your filters need attention depends on:
- How frequently the system is used
- Whether you have pets
- Dust levels in the property
- Whether the room is used commercially
- The manufacturer’s recommendations
During periods of frequent summer use, it is worth checking filters approximately every few weeks.
If the system is used less frequently, they may need cleaning less often.
Commercial environments may require a more regular maintenance schedule.
Always refer to the manufacturer’s instructions for your particular unit.
Before you start
Before cleaning your air conditioning filters:
- Switch the system off.
- Allow the indoor fan to stop completely.
- Make sure you can access the unit safely.
- Check the manufacturer’s instructions if you are unsure how the front panel opens.
Never climb onto unsuitable furniture or attempt to access a unit that cannot be reached safely.
If the system is mounted at height or you are unsure what you are doing, contact an engineer instead.
Step 1: Open the front panel
Most wall-mounted units have a front cover that gently lifts upwards.
The filters are usually immediately visible behind the cover.
Do not force the panel.
If it does not open easily, consult the user manual for your specific model.
Step 2: Remove the filters carefully
The main mesh filters will usually slide or lift out.
Take note of how they are positioned so that you can replace them correctly afterwards.
Some systems may also contain additional specialist filters.
These may require different cleaning or replacement procedures, so do not wash anything unless the manufacturer confirms that it is suitable.
Step 3: Remove loose dust
If the filter is only lightly dusty, a vacuum cleaner with a soft attachment can often remove loose material.
Be gentle.
The filter mesh can be damaged if it is scrubbed aggressively or vacuumed with excessive force.
Step 4: Wash the filters if appropriate
Many reusable mesh filters can be washed using lukewarm water.
Avoid:
- Boiling or very hot water
- Strong cleaning chemicals
- Bleach
- Abrasive brushes
- Aggressive scrubbing
If necessary, a small amount of mild detergent may be appropriate, but always follow the manufacturer’s guidance.
Step 5: Let the filters dry completely
This is important.
Do not put wet filters straight back into the air conditioning unit.
Allow them to dry naturally and completely before refitting them.
Avoid using intense direct heat, hairdryers or other methods that could damage the filter material.
Step 6: Refit the filters
Once completely dry, carefully put the filters back into their original position.
Make sure they sit properly in their guides before closing the front panel.
You can then switch the system back on.
What should a clean filter look like?
A clean reusable filter should allow you to see the mesh clearly without a thick layer of dust covering it.
If the filter is damaged, torn or heavily discoloured, speak to your installer or manufacturer about whether it needs replacing.
Can I clean the inside of the air conditioning unit myself?
Basic filter cleaning is very different from professional air conditioning maintenance.
We do not recommend dismantling internal components, spraying chemicals into the unit or attempting to clean areas that are not designed for user access.
An engineer can safely inspect and clean other parts of the system as part of professional servicing.
What if my air conditioning still smells after cleaning the filters?
Dirty filters can sometimes contribute to unpleasant smells, but they are not the only possible cause.
If a musty or unusual smell continues after the filters have been cleaned, there may be contamination or moisture elsewhere within the indoor unit.
That is a good reason to arrange a professional inspection.
What if airflow is still weak?
Cleaning a clogged filter may improve airflow immediately.
If airflow remains noticeably weak afterwards, there could be another issue affecting the system.
Possible causes can include contamination elsewhere in the unit, fan problems or other faults requiring investigation.
Filter cleaning is only part of air conditioning maintenance
Keeping filters clean is an important piece of basic maintenance, but it does not replace professional servicing.
A service allows an engineer to inspect parts of the system that cannot be properly assessed through routine user cleaning.
For systems that operate regularly, especially commercial installations, planned maintenance is an important part of keeping equipment reliable and efficient.
A simple habit that can make a real difference
Checking your filters regularly only takes a few minutes, but it can help your system perform as intended and may prevent unnecessary problems.
If you haven’t looked at your filters since the beginning of summer, now is a good time to check them.
Need your air conditioning serviced?
If your filters are clean but the system is still struggling, making unusual noises, producing smells or showing other signs of a problem, Oxford Air Conditioning can help.
We provide servicing, maintenance and repairs for domestic and commercial air conditioning systems across Oxfordshire and the surrounding area.
Get in touch with our team to arrange a visit.
Book service & repair
If you have any enquiries, please call us on 01235 524411, fill in our short contact form, or schedule a survey now.