Every air conditioner has two coils: one indoors that absorbs heat from the room, and one outdoors that releases it. In Dubai both collect dust quickly, and a coated coil cannot move heat properly. The unit keeps running, but it cools less and costs more.
The room takes longer to cool
If the AC used to cool the room in twenty minutes and now needs an hour, the coil is a likely cause. Dust on the fins acts like a blanket.
The air is not as cold as it was
Hold your hand at the vent. Air that feels cool but not properly cold, with the unit working normally otherwise, often points to a dirty indoor coil.
Your DEWA bill has crept up
A unit that has to run longer for the same result uses more electricity. A rise in summer bills with no change in how you use the AC is worth investigating.
Water is dripping indoors
A dirty coil can ice over, and when the ice melts the drain tray overflows. Dust washed off the coil can also block the drain line.
There is a musty smell
A damp, dusty coil is an ideal place for mould. A stale smell when the AC first switches on usually comes from the coil or the drain tray.
What you can do yourself
Rinse the filters monthly, and keep the outdoor unit clear of leaves, boxes and anything else that blocks airflow. Leave the coil fins alone — they bend very easily.
How often to clean them
For most Dubai homes, once a year before summer is a sensible routine. Homes near construction, sand or the sea may need it more often.
