Split AC filter: lift the panel, brush off the dust, dry it in the shade

The mesh filter behind the front cover of your indoor unit is the first thing to catch the dust in your home. Once it clogs, the unit moves less air and runs longer. The US Department of Energy says swapping a dirty, clogged filter for a clean one can cut an air conditioner’s energy use by 5 to 15 percent.

How often

The department recommends cleaning or replacing the filter every month or two during the cooling season, and more often if the unit runs constantly, the air is dusty, or you keep pets with fur.

The steps

These come from LG’s support page for wall-mounted units, which notes that your model may look different from its pictures:

1. Switch the unit off and cut the power before you touch it.
2. Lift the front panel of the indoor unit and slide the filter out. On some models the filter sits over the top air intake instead; the method is the same.
3. Remove the dust with a vacuum cleaner or a soft brush.
4. If it is badly soiled, wash it in water with a neutral detergent.
5. Dry it somewhere well ventilated and shaded, out of direct sun, then put it back and close the panel.

When to replace instead

• Some filters are not meant to be washed at all and must be replaced regularly. Your manual will say which kind you have.
• Filters are consumables. Replace them at the end of their life, even while the unit is under warranty.
• A torn, warped or discoloured filter should be replaced through the dealer’s spare-parts desk.
• Extra filters, such as deodorising ones, vary from model to model.

Beyond the filter

The Department of Energy also advises checking the indoor evaporator coil once a year and cleaning it as needed, and keeping at least 0.6 metres around the outdoor unit clear of clutter and plants so air can flow.

Photo: a split-unit filter clogged with dust. By Gerardolagunes, CC BY-SA 4.0, via Wikimedia Commons, rotated by Kuwait One.

Source: LG UAE Support, “How to clean and replace air-conditioner filter” (lg.com/ae), and the US Department of Energy, “Maintaining Your Air Conditioner” (energy.gov), both read on 13 October 2026.