'Chiller free' means the landlord pays the district-cooling (air-conditioning) charge, so you won't get a separate cooling bill - though you still pay DEWA for electricity, water and gas. It's effectively baked into the rent. Always confirm it's written in the tenancy contract; if cooling isn't named as the landlord's cost, you could still be billed for it.
Rules and eligibility criteria change — confirm the current position with the relevant authority before acting. This is general information, not legal advice.