AC repair vs replace: when is an old unit not worth fixing in the UAE?

My rough rule: if the repair is more than about 40% of a new unit AND it is past 8 to 10 years, replace. Yours ticks both. Two red flags in what you wrote: needing gas every summer means a leak that never got fixed, so you are paying for gas top-ups that vent straight back out — and a tired compressor is the one part where fixing it rarely makes economic sense on an old unit.

Also factor the running cost: a modern inverter unit can meaningfully cut consumption over a Gulf summer, so the real comparison is not just sticker price versus repair, it is repair versus (new price minus the DEWA saving).

This is the bit people miss — a 9-year-old unit running at reduced efficiency runs longer for the same cooling, so an old unit that technically works still costs you every month. Over two summers, replacing is sometimes the cheaper path, not the expensive one.

One caveat so nobody bins a good unit: if the rest of it is sound and it is just a fixable fault like a capacitor or fan motor, repair all day. It is specifically the compressor plus age plus annual gas combo that tips it to replace. If you do go new, get it sized right and fitted properly — a sloppy AC installation can waste the efficiency you just paid for.