HEPA filter modules can be ordered with or without fan power. Those without fan power are best suited to facilities where there’s enough air-handling unit fan static pressure available to force air through the filter. (Noise can be a concern with fan-powered HEPA units, but some models have a speed control feature that allows the user to adjust the airflow as desired, offering some noise mitigation.)
Facility managers may want to periodically re-examine the choice of the materials used to construct filters they are buying. Materials such as PTFE and PVDF membranes have been popular for chemical applications; however, today’s alternative filtration materials include ultra-high molecular weight polyethylene (PE) and polysulfone (PS), which enable the production of different filter sizes and shapes. These materials can be used to create specific pore structures that allow facilities to tailor the equipment to their needs.
This cleanroom tip was taken from “The Ins and Outs of Cleanroom Filters,” which appeared in the February 2013 issue of Controlled Environments.