When the heat arrives, the air conditioner becomes king of the house again. But before you reach for the remote it is worth knowing how to clean an air conditioner properly: a dirty unit cools less well, uses more electricity and spreads the dust and spores it has collected for months around the whole room. The good news is that cleaning the air conditioner filters is a simple job you can do yourself in fifteen minutes, with no technician and no expensive products. In this guide we go through it step by step so your unit works like new.
Why cleaning your air conditioner matters so much
The unit draws in the air from the room, cools it and sends it back. Along the way, the filters trap dust, pet hair and particles. If you never clean them, three things happen: the airflow drops and the room takes longer to cool; the motor works harder and uses more electricity; and, worst of all, trapped moisture encourages mould and bad smells that you end up breathing in. Cleaning it is not just hygiene: it is savings and health. A clean unit can recover much of its lost efficiency, and you see that directly on the summer bill.
How to clean a split air conditioner at home
Most homes have a wall-mounted unit, so let us get straight to how to clean a split air conditioner step by step:
- Switch it off and unplug it. Never work on the unit while it is connected.
- Open the front cover. It lifts gently until it stays in place; underneath you will see the grille-style filters.
- Remove the filters carefully. Vacuum off the coarse dust, then wash them under the tap with lukewarm water and a little mild soap. If they are very dirty, leave them to soak for a few minutes.
- Dry them completely in the shade before putting them back. Fitting them damp creates mould.
- Clean the casing and the louvres with a slightly damp microfibre cloth. For the narrow vents, a small brush or a cotton bud works a treat.
- Check the drain. If it drips or smells, there may be dirt in the drainage pipe.
For this routine all you need is microfibre cloths, a soft brush and mild soap. If you want everything to hand, take a look at our selection of home products, where you will find practical cleaning accessories for everyday use.
The outdoor unit counts too
Plenty of people forget the unit outside, on the facade or the balcony. That unit expels the heat, and if the grilles fill up with dust, leaves or fluff, performance nosedives. With the system switched off, remove any visible dirt and gently vacuum or brush the outer grilles. Do not use a pressure washer, as you can bend the aluminium fins. If the unit is high up or you cannot reach it safely, leave it to a professional: your safety is worth more than a quick clean.
How often should you clean an air conditioner
The million-euro question is how often to clean an air conditioner. The simple rule is this:
- Filters: every 2 to 4 weeks during the months of heavy use. If you have pets or allergies, make it every two weeks.
- General clean (louvres, casing, drain): once at the start of the season and again in the middle of summer.
- Technical service (refrigerant, internal coils): once a year, ideally in spring, before the first hot days.
One trick: note the day you cleaned the filters in your phone calendar. That way you never let it slide and the unit always performs at its best.
Mistakes worth avoiding
There are very common mistakes that shorten the life of the unit. Do not use abrasive products or solvents on the plastic, as they yellow it and dry it out. Do not refit the filters while they are wet. Do not block the air outlet with furniture or curtains. And do not wait for a bad smell before you act: by the time you can smell it, the mould has been there a while. Preventive cleaning always costs less than a repair. And if you pair the air conditioning with small allies around the home such as fans or thermal curtains, you will cool the house while using less energy.
Conclusion
Knowing how to clean an air conditioner is one of those routines that gives a lot in return for very little: healthier air, better cooling and a more contained bill. Set aside fifteen minutes every couple of weeks for the filters and do a more thorough clean at the start of the season, and your unit will thank you all summer long. At Velia Select we choose home products designed to make life easier; drop by the shop and get your home ready for the hottest days.