How often should AC coils be cleaned in the UAE — and can I do it myself?

There are two coils and they're very different jobs:

Outdoor condenser coil (the dusty balcony box) — this one you *can* do yourself, carefully: - Switch the unit off at the isolator, not just the remote. - Rinse from the inside out with a normal hose on low pressure. Never a pressure washer — it folds the thin aluminium fins flat and then it can't shed heat. - A soft coil brush or a fin comb sorts light bending. Keep water off the electrical box on the side.

Indoor evaporator coil (behind the filters) — leave this to a technician. It's delicate, it sits right next to the blower, live wiring and the drain pan, and doing it properly means a chemical coil clean and flushing the drain. Not a DIY job.

Frequency here: at least once a year, and twice if you're near ongoing construction, on the coast (salt), or you run the AC hard year-round. Signs they're overdue: weak cooling, a creeping DEWA bill, ice on the pipes, or a musty smell. If you'd rather have both coils, the drain and the gas checked in one visit, that's a standard AC service. Background on the part that actually does the cooling: the evaporator coil.