TESTING STANDARDS

ASHRAE 52.2 (MERV)

Minimum Efficiency Reporting Value (MERV) is a value expressed on a 16 point scale to reference appropriate particular matter removed in 3 different range groups. The higher the MERV rating, the greater the percentage of particles captured on each pass. This testing method is conducted at seven different airflow rates, with the final resistance being twice that of the initial resistance. 

ASHRAE 52.2 APPENDIX J

Created in 2008, Appendix J was added as an optional step to identify drops in filter efficiency. These filters undergoing this test are referred to as MERV A, carrying both a MERV rating and a MERV A value.

ISO 16890

The International Organization for Standardization has developed a test basing filter ratings on the average of the mass of particular matter removed.  The smaller the value in the rating name and the higher reported efficiency means a more efficient particle removal. 

ISO 29463 | EN 1822

HEPA, or High-Efficiency Particulate Air, represents a filtration technology renowned for its exceptional efficiency in capturing a wide spectrum of particulate matter, ranging from the minutest to the most substantial contaminants. 

The IEST (Institute of Environmental Science and Technology) is the leading technical, nonprofit membership association that connects professionals who deal with controlled environments.  By testing our products to IEST, Zephyr Filtration is positioned to deliver highly efficient filters.