Air filter requirements are based on science and real-life testing, not calculated data. A program of best practices for air filtration needs can be developed with little or no capital investment. There are several key factors in selecting air filters to optimize energy consumption.
Start with understanding what filter efficiency is required to protect the process, environment, or people. Unfortunately, there is a paradoxical relationship between energy savings and filter efficiency. The higher the grade selected (should be a minimum efficiency reporting value of MERV 13 or F7), the higher the energy consumption as the resistance will increase as efficiency increases. Do not use coarse fiber or synthetic media; select glass or fine fibers.
Once the filter grades have been established, along with the number of filtration steps and where these grades are located within the air handling unit, selection should be based on optimizing the pressure drop across each step and crucially establishing a change out point to maximize life at the lowest operating cost based on scientific data.
This cleanroom tip was taken from “Science-based Savings for Filter Selection and Maintenance,” which appeared in the October 2012 issue of Controlled Environments.