Air Conditioning Cleaning in Cairns

The smell is coming from the barrel fan

Turn a split system on after a few weeks off in the wet season and the first thirty seconds tell you everything. That smell is biological growth, and people almost always go looking for it in the wrong place.

Filters are the easy part, and any householder can pull them out and wash them under a tap. The growth causing the odour sits further in, on the face of the evaporator coil and, above all, in the barrel fan behind it. A barrel fan is a long cylinder with dozens of small curved blades, and each blade holds a pocket of dust bound together by condensate. Nothing you can reach with the front cover off touches it. That is why so many units smell exactly the same a week after a cheap clean.

What a proper clean reaches

The unit gets bagged so the water goes into a catchment rather than down your wall and across the floor. The coil is treated and rinsed through, the drain pan underneath it is cleared out, and the barrel fan is cleaned properly, which on some models means flushing it in place with the right nozzle and on others means taking it out.

Rinsing is not optional. Foaming products sprayed on and left to drain away sound convenient and leave chemical residue sitting in the air you then breathe all night. Whatever goes on comes back out, and the drain line gets flushed afterwards, because everything lifted off the coil ends up down there and is a very common cause of a blocked drain a month later.

Fins matter too. Bent fins across the coil face restrict air, and combing them straight belongs in the job rather than on a list of extras.

Why it comes back faster here

An evaporator coil is a cold wet surface in a moving airstream. In a dry climate it dries out between runs. In Cairns the ambient humidity means it can stay damp for hours after shutdown, which is precisely the condition growth wants, and it is why units up here need cleaning more often than the manual written in Osaka suggests.

There is a free habit that helps. Most remotes have a fan only mode. Running the indoor fan for ten or fifteen minutes after you finish cooling dries the coil out and slows regrowth noticeably. If the unit has a dry or self-clean function, use it. Neither replaces a clean, but both stretch the interval between them.

The wet season is the peak, so late in the dry is the sensible time to have it done, rather than in the middle of the monsoon when it is already bad.

When a clean will not fix it

If the smell is sewer-like rather than musty, the cause is usually the drain and the trap rather than the coil, and a clean will disappoint you. If the drain pan is cracked or the indoor coil is corroded through, cleaning tidies the symptom and leaves the cause behind, and on an old unit the honest advice is to put that money toward replacing it.

We also will not pressure wash a coil. The fins are thin aluminium, and flattening them buys a coil that looks clean and moves less air than it did before.

If it smells and you want a straight answer on whether a clean will fix it, call 0489 266 523 and describe the smell first.