How to Clean Your AC Air Filter Correctly: 5 Steps

Preparation Before Cleaning

Before touching the filter, switch the unit off and disconnect the power. Do not open any part of the unit while it is live. Lay a towel or sheet of newspaper on the floor below the unit to catch any dust that falls when the filter is removed.

The method for opening the front panel varies by model. Some require you to lift the panel upward; others have release tabs on the side. If you are unsure, consult the instruction manual or look carefully at where the panel joins the casing — never use force to pry it open, as you may break the clips.

Five Cleaning Steps

Step 1: Switch off the unit and disconnect the power. Step 2: Gently open the front panel, locate the filter, and slide it out in the direction indicated — note that some models have more than one filter, so remove them all. Step 3: In a sink or bathtub, hold the filter so that the clean side (the side that faces inward, toward the machine) is uppermost, and rinse with tap water so that the water flows from the clean side through to the dirty side (the side that faces the room air). Rinsing in this direction pushes the dust particles back out the way they came in, rather than embedding them further into the mesh.

Step 4: If the dirt is sticky or greasy, dissolve a small amount of mild neutral detergent in water, soak the filter for a few minutes, then gently rub with a soft-bristled brush or your fingers, and rinse thoroughly with clean water. Do not use hot water (it can warp the plastic frame) or strong alkaline cleaners (they can corrode the filter mesh). Step 5: Place the filter in a cool, shaded, well-ventilated spot and allow it to dry completely before reinstalling. Reinstalling a damp filter accelerates mould growth inside the unit.

• Rinse from clean side to dirty side (pushes dust out the right way)
• Avoid hot water and strong alkaline cleaners
• Rub gently — do not scrub hard (protects the mesh grid)
• Fully dry before reinstalling (prevents mould growth)
• When reinstalling, confirm orientation and that clips are securely engaged

The Limits of Filter Cleaning

Filter cleaning is basic routine maintenance, but it only deals with the dust on the outermost intake layer. Grime on the evaporator coil, the fan wheel (blower), the drain pan, and deep inside the drain pipe cannot be removed by cleaning the filter — a technician needs to open the unit for a deep clean.

If cooling performance, musty odours, or dripping do not improve after the filter is cleaned, the source of the problem is deeper inside the unit, and a professional deep clean or diagnostic is needed.

Air Filter Cleaning Step Checklist

• Switch off the unit and disconnect the power
• Place a towel below the unit to catch falling dust
• Consult the instruction manual and open the panel using the correct method
• Gently remove the filter (do not force it)
• Rinse from the clean side toward the dirty side under running water
• If needed, soak briefly with neutral detergent, rub gently, and rinse thoroughly
• Place in a cool, shaded spot and dry completely
• Confirm the filter is fully dry, reinstall it, and ensure the clips engage
• Restart the unit and confirm normal operation

Frequently asked questions