How often should you clean your AC? A practical schedule for filters and deep cleans

Three levels you should not confuse

The first level is cleaning the filter, and that is your job. You take the mesh filters out of the indoor unit, wash them and dry them in a few minutes. It is the single most useful thing you can do to keep the cooling strong and the air clean.

The second level is the deep clean, and that is the technician’s job. It covers the indoor coil, the blower wheel, the drain tray and drain pipe, and washing the condenser in the outdoor unit. It needs tools, a collection cover to protect the wall and furniture, and sometimes dedicated cleaning products.

The third level is full maintenance, which is the deep clean plus checks on pressure, refrigerant, the capacitor, the wiring and the compressor. You will find the details on our AC maintenance page. Many people ask for a clean when they need maintenance, or the reverse, so know what you are requesting before you compare prices.

Filters: every two weeks in summer

In the summer months, when the AC runs for long hours, clean the filter about every two weeks. After a dust storm, check it the same day, because it can fill in one day as much as it normally does in two weeks. In winter and the milder months, once a month is usually enough, unless there are children, people with allergies or asthma, or pets in the house, in which case do it more often.

The method is simple, but the details matter. Switch the AC off before opening the cover, and wash the filter in lukewarm water, without very hot water or a stiff brush that could tear the mesh. Most important of all, let it dry completely in the shade before putting it back. A damp filter collects dust quickly and starts to smell, a mistake I see often from people in a hurry.

Deep cleaning by level of use

A lightly used AC, such as one in a guest room or one that runs only a few hours a day, usually needs one deep clean a year before summer. For bedrooms and living rooms in most homes, where the AC runs every day, I recommend once before summer and again in the middle of it or after the dust season.

A majlis that runs all day, or a home near dirt roads or building sites, needs at least two deep cleans a year, and sometimes more. Shops, restaurants and offices are a different matter. Kitchens and shopfronts open to the street need a tighter schedule, and a commercial maintenance contract with fixed visits suits them best.

These figures are guidance, not a rule. The best indicator is what the technician tells you about the coil after the first clean. If he says it was thickly coated after only six months, you know your schedule.

Your city changes the schedule

In Riyadh and the central region, dry dust and sandstorms are the biggest factor. Dust clogs filters and condensers quickly, so a clean before summer and after the dust seasons matters most. Details are on our AC cleaning in Riyadh page.

In Jeddah and the western coastal cities the challenge is humidity. There is a lot of condensate, a greater chance of mould and smells in the drain tray and fan, and salt that affects the outdoor unit. So cleaning here focuses on the drain tray, the drainage and disinfecting the indoor unit. See AC cleaning in Jeddah.

In Dammam and Khobar you get both, wind-blown dust and Gulf humidity, which together form sticky deposits that are harder to remove than Riyadh’s dry dust. Here two cleans a year become necessary for heavily used units. See AC cleaning in Dammam.

Signs that say do not wait

Whenever the last clean was, if you notice any of these signs, book a clean now:

• A bad or musty smell when the AC starts.
• Weak airflow even though the filter is clean.
• Black specks or dust coming out of the vent.
• Water leaking from the indoor unit.
• Weaker cooling than usual and a higher bill.
• Sneezing or allergy symptoms that get worse when the AC runs.

Some of these signs can also point to other faults, so if weak cooling is the main problem, see our guide AC not cooling.

What a deep clean should include

The word “cleaning” means different things to different companies. Some just spray the coil from the front, others remove the covers and the blower wheel and wash the outdoor unit as well. So I always ask four things before comparing. Does the clean cover the coil, the blower and the drain tray, or the coil only? Is a collection cover used to protect the wall? Is the drain pipe cleared and the water flow checked? And is the outdoor condenser washed, and how will the technician reach it if it sits on a roof or a high facade?

Ask about the products used as well, whether they are made for air conditioners and whether they are rinsed off properly. Chemical residue left on the coil attracts dust again very quickly.

Each type has its own routine

The wall-mounted split is the most common. Its filter is easy to reach and you can clean it yourself, while the coil and blower wheel need a technician with a collection cover. Make its deep clean a fixed date every year. A window AC is exposed directly to dust and sun outside, so it gets dirty faster, and cleaning it properly usually means taking the unit out of the wall, so do it at the start of every summer at least.

A cassette unit in a majlis, office or shop has its filter in the ceiling, which means a ladder, and a larger drain tray where mould can build up in humid weather, so do not wait for a smell. Central and concealed systems have filters in the return grilles or in the unit itself, and the ducts collect dust over the years. These systems need a technician who knows them well. Read our central AC page. Mention your AC type when you request offers so the company brings the right tools.

Should you clean it yourself?

Cleaning the filter and wiping the outer cover is safe. Spraying water or chemicals onto the coil inside the indoor unit, or removing the fan, can push water onto the circuit board or bend the fins, and can void the warranty. I have seen boards burnt out by a supermarket spray can, so leave this to a technician.

If you have several ACs, have them all cleaned in one visit. It is easier to arrange and often cheaper. You can request cleaning offers and mention the number and type of units.