MERV Rating

Minimum Efficiency Reporting Value, or MERV rating is a method for rating the effectiveness of filters. It was developed by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE).

A MERV rating consists of two parts, a MERV number and an air flow rate. The combination of efficiency rating and air flow rate ensure that filters are chosen properly for a particular application. Earlier rating systems did not specify the air flow rate used in testing, making equity of filtration difficult as some filters may have been tested with lower airflow rates than others.

The MERV rating system is also open ended, making it possible to expand the rating scale in the future if filter technology improves.


We have moved

New address
2115 - 13700 Mayfield Place
Richmond BC V6V 2E4

new location image