Simple Guide to Cleaning Aircon Filters in Humid Climates Like Singapore

Air conditioners bring more than just comfort. Because of the hot and humid weather in Singapore, AC systems are a necessity. But many people forget one important thing—cleaning the aircon filters.

When the filters are dirty, your AC has to work harder, which uses more electricity and cools your home less. Even worse, it can circulate dirty air into your home.

This guide will show you how to clean aircon filters to keep the air in your home fresh.

What Aircon Filters Do

An aircon filter, or simply a filter, traps unwanted particulate matter in the air as it passes through its mesh. In general, they improve indoor air quality around the space but only when you keep your AC filter clean.

The filter can remove more contaminants from the air the finer its mesh is.

Common Types of Filters

You must understand what type of aircon filter you have before cleaning it. Different filters need different care, and some shouldn’t be cleaned at all.

Here are the most common types in Singapore.

Fibreglass Filters

These are the most basic and cheapest filters. They are made from thin layers of fibreglass and mainly catch bigger dust particles.

What you should know about fibreglass filters:

• Cheap and disposable
• Usually have a cardboard frame
• Only catch large dust, not tiny allergens
• Not washable (replace when dirty)
• Lower filtration efficiency

These filters are okay for basic use but not great for dusty and humid environments.

Pleated Filters

These filters are made of folded (pleated) fabric or paper, which gives more surface area to trap dust and dirt.

What you should know about pleated filters:

• Better than fibreglass at catching small particles
• The folded design helps trap more dust
• Medium price
• Some are washable, others are not
• Good for homes with mild allergies

These filters balance performance and cost, making them a common choice.

HEPA Filters

HEPA stands for High-Efficiency Particulate Air. These filters remove very small particles and are great for people with allergies or asthma.

What you should know about HEPA filters:

• Can trap small particles (as small as 0.3 microns)
• Ideal for allergy and asthma sufferers
• Used in spaces where high air purity is needed

Electrostatic Filters

These filters use static electricity to pull in dust and particles. Some can be washed and reused.

What you should know about electrostatic filters:

• Can be washable or disposable
• Acts like a magnet for dust
• Better for the environment if washable
• Good at catching small to medium particles
• Mid-price, but washable ones save money over time

Washable electrostatic filters work well in Singapore since they can be cleaned often to avoid mould.

How to Know If Your Filter Is Washable or Disposable

If you are not sure if your filters can be cleaned, refer to the guide below.

1. If it has cardboard edges, it is likely disposable. Do not wash.
2. Check the labels and look for words like “Washable” or Disposable” on the frame.
3.  Washable filters feel stronger and often have plastic frames. Paper-like ones are disposable.
4. Refer to your AC manual as it will tell you what type of filter to use and how to maintain it.
5. Washable filters usually have arrows moulded into the plastic frame, not just printed on cardboard.

Important tip: If you are still unsure, it is safer to replace the filter than risk damaging your aircon or breathing dirty air.

How Dirty Filters Affect Energy Efficiency and Electricity Bills

When your aircon filter is full of dust, pet hair or dander, or mould, it blocks the airflow. Here is a simple explanation of how your AC needs to operate harder just to keep your room cool.

With a clogged filter, the fan has to push harder to move the air. And when air cannot flow freely, it takes longer to cool the room. So your aircon stays on longer and uses more energy.

If your filter is really dirty, your aircon might cool up to 20 to 25% less effectively. That means you’re paying more money but are less comfortable.

Signs That Your Filter Needs Cleaning

Let’s discuss the warning signs that your filter needs cleaning or replacement.

Weak Airflow

If…

1. The air feels weak even when the fan is on high
2. Some rooms cool slower than others
3. Cooling feels uneven around your home

Strange or Musty Smells

1. A musty or mouldy smell when you turn on the AC
2. A dusty or “dirty sock” odour from the vents

These smells could mean mould or bacterial growth in the filter. A clean filter shouldn’t smell at all.

Dust Buildup on the Filter

1. The filter looks grey/black
2. Thick dust covers the surface
3. Clumps of dust stuck in the mesh

Filters may get dirty in just two to four weeks during heavy AC use. So if you see dust on the filter, it’s time to clean it (or get it cleaned).

Aircon Runs Longer Than Usual

1. The aircon takes longer to cool your room
2. It keeps turning on and off more often
3. It makes more noise than normal

More Allergy Symptoms

1. More sneezing or coughing at home
2. Asthma or breathing issues are getting worse
3. Dust collecting faster on furniture

Higher Electricity Bills

1. Your electric bill goes up even though your usage hasn’t changed
2. If your bill increases unexpectedly, the filter might be to blame.

How to Clean Your Aircon Filter

Before you start, safety first

Always switch off the aircon or flip the circuit breaker to guarantee safety. Your aircon may have specific instructions, so it’s always a good idea to refer to them before starting any cleaning.

Wear a mask and gloves especially if you are sensitive to dust or mould. Clean your filters in a bathroom or on a balcony to avoid making a mess.

The last thing to keep in mind is to set aside enough time as filters need time to dry completely.

What you will need

• Screwdriver (for some units)
• Vacuum cleaner with brush attachment
• Soft brush or toothbrush
• Mild detergent or dish soap
• Warm water (not hot!)
• Spray bottle
• Clean cloth or sponge
• Towel or mat to protect your floor
• Fan (optional, helps speed up drying)

The cleaning steps

1. Turn off the unit. Wait 5-10 minutes before handling the unit.
2. Remove the filter. Open the front panel and pull the filters out gently (for split units). For window units, remove the front grille to access the filter. For ceiling units, press the side tabs to access the filter from behind the grille.
3. Look for holes/tears, mould spots, fraying or flimsy material, or bent frames. If you see that it looks worn or damaged, it’s better that you replace it.

How to clean different types of aircon filters

For quick cleaning of washable filters,

1. Vacuum both sides gently.
2. Rinse under lukewarm water, from the clean side to the dirty side.
3. Use a mild soap solution and a soft brush if needed.
4. Rinse again until the water runs clear.

For very dirty filters,

1. Soak in warm, soapy water for 10-15 minutes.
2. Swirl occasionally to loosen the dirt.
3. Rinse thoroughly.

For electrostatic filters,

1. Vacuum gently.
2. Spray with a mix of water and white vinegar.
3. Let it sit for 10 minutes and then rinse.
4. Don’t scrub too hard. It can damage the filter.

For HEPA or non-washable filters,

1. Gently vacuum only.
2. If it’s still dirty, replace it.
3. Never use water or soap.

Drying filters in humid weather

1. Shake off extra water.
2. Pat dry with a towel. Don’t rub.
3. Let it air dry in a shaded, breezy spot—never in direct sunlight.
4. Drying takes two to four hours or more in humid conditions.
5. Use a fan to speed up drying, if you’re short on time.

It’s important to remember never to put a damp filter back in to avoid mould growth.

Reinstalling the filter

Once the filter is completely dry, follow these steps.

1. Make sure it is facing the right way. Be guided by the arrows.
2. Fit it snugly back into place.
3. Close all panels properly.
4. Turn the power back on and run the unit for a few minutes.
5. Check for airflow and strange sounds.

Conclusion

DIY is great for regular maintenance of your aircon filters, but call for professional servicing at least once or twice a year to perform a deep clean.

For affordable aircon services, partner with KungFu Helper. Send us a message here to book an appointment.