MERV rating (air-filter efficiency)

MERV (Minimum Efficiency Reporting Value) is the standard 1–16 scale rating how effectively an air filter captures particles — the higher the number, the finer the dust, pollen and smoke it traps. In the dusty UAE a better filter (roughly MERV 8–11 for a home) genuinely improves indoor air quality and keeps the evaporator coil cleaner for longer. But here's the catch people miss: a too-high-MERV filter in a system not designed for it restricts airflow — the AC then works harder, cools worse, and can even freeze the coil. So you match the filter to what the unit can actually pull air through, not just buy the highest number on the shelf. (A cheap washable mesh filter's effective rating is low; for real filtration you fit the right-MERV pleated filter and change it on schedule.) Getting the filtration right for your unit is part of efficient, well-set-up cooling.