Relative humidity (RH)
Also called: humidity, rh, indoor humidity
Relative humidity (RH) is how much water vapour the air is holding compared with the most it could hold at that temperature, written as a percentage. It matters indoors because comfort isn't only about temperature: at the same 24°C, air at 70% RH feels clammy and sticky while air at 45% feels fresh. Coastal Dubai air is very humid, so a large part of an air conditioner's job is to dehumidify — moisture condenses on the cold evaporator coil and drains away. When indoor RH stays high you get the tell-tale signs: condensation and mildew on cold surfaces, a musty smell, and rooms that feel cold but clammy. The usual culprits are a dirty coil, run-times that are too short, or an oversized unit that chills the air quickly without running long enough to wring the moisture out. Keeping the coil and condensate drain clean so the system genuinely pulls humidity down — not just the temperature — is a core reason to keep up with home AC cleaning in Dubai.
Related terms
Evaporator coil
The cold indoor coil that actually absorbs heat and dries the air.
Condensate drain
The line that carries away the water your AC pulls from the air — and the usual cause of ceiling leaks.
Biofilm
The slimy microbial layer that builds up inside a neglected water tank or pipe. It's why tank cleaning is a water-quality issue, not just a taste one.
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