Does the HEPA filter truly provide 99.97% HEPA filtration?
A filter made with HEPA media may or may not provide true HEPA efficiency. Serious leakage can go undetected if filters are not individually tested and certified at the end of the manufacturing process in accordance with IEST-RP-CC001.3 guidelines for Type A HEPA filters. Even the tiniest pinhole leaks in the media or breach of the seal between the media pack and the filter frame can cause the filter to fail efficiency requirements. If this happens, contaminated air can pass through the filter and be exhausted into ‘clean’ areas of the facility. HEPA testing requires very specific procedures using a thermally generated mono-dispersed aerosol and a laser particle counter. Test results, including test airflow, percent penetration, date of manufacture and other detailed information must be included on a label affixed to the filter. Testing should be conducted at the rated airflow of the machine. A filter designed for and tested at 1,000 cfm or 1,100 cfm may provide significantly lower eff
