Minimum efficiency reporting value. A standard laboratory test measures capture of particles in three size bands from 0.3 to 10 microns, and the MERV number reflects the worst-case results. MERV 8 is a common baseline for commercial buildings, and MERV 13 stops at least half of the particles in the finest band, 0.3 to 1 micron. Higher MERV filters with too little face area add pressure drop, so filter racks and fan capacity must be checked.
Owner wants MERV 13 in every unit, fine, but on the small RTUs we need 4 inch deep filters or the static goes through the roof.
Also heard as
- MERV rating
Related terms
IAQ
Indoor air quality: how clean and healthy indoor air is, judged by contaminants, ventilation, humidity and comfort.
Static pressure
The pressure air exerts outward on duct walls, the resistance a fan works against, measured in inches of water column.
AHU
Air handling unit: the cabinet of fans, coils, filters and dampers that conditions and moves air through a building's ducts.