Air Filtration Products
Air Purification
Extended Bag Filters
Extended Surface Rigid Filters
Gas Phase Filtration
Hardware
Hepa Filters
Maintenance Products
Pad Media
Panel Filters
Pleated Filters
Spray Booth Filters
Ultra Violet Lighting

Liquid Filter Products
Cartridge Replacement
Housings


Clean Room Products
Ceiling Components
Ceiling Grids
Doors/Curtains/Grills
Hepa Clean Chamber
Ionizing Blower
Laminar Flow Workstation
Modular Hardwall
Modular Softwall
SAM Fan Filter Units
Static Bar
Terminal Hepa Diffusers
Ultra Violet Lighting





Most Common Questions
What should I know about ASHRAE Efficiency
When should I change my filters?
MERV Filter Efficiency Guide


What should I know about ASHRAE Efficiency


What should I know about ASHRAE Efficiency.pdf


What should I know about ASHRAE Efficiency?

Understanding MERV or the Minimum Efficiency Reporting Value

How the ASHRAE 52.2 Helps You Select an Air Filter

For 30 years tests for air filters were done according to ASHRAE 52.1. This test provided an efficiency rating such as a 30%, 65%, 90%, etc.. This system is relatively easy to understand. However, it has some major deficiencies in that it does not provide a very good guide for selecting filters for particular contaminants. In order to do that effectively you need to know two things – one, the particle size of the contaminant you are trying to remove and two, the level of efficiency of the filter on that particle size. Thus the ASHRAE 52.2 test was developed to provide this particle size efficiency data.

Obtaining the Data

An air filter's performance is determined by measuring the particle counts upstream and downstream of the filter being tested. Particle counts are taken over the range of particles six times. One begins with a clean filter and then uses that same filter 5 additional times.


.