How Often Do You Need to Change HEPA Filters in Cleanrooms?
High-efficiency particulate air (HEPA) filters are mechanical air filters designed to remove undesirable airborne particles from a space. They’re highly effective in cleanroom environments where clean air is critical to operations, such as in hospitals, laboratories, manufacturing facilities, and pharmaceutical processing plants.
Filters must be able to capture at least 99.97% of airborne particles as small as 0.3 microns in order to be classified as true HEPA filters. These filters capture dust, pollen, mold spores, bacteria, and viruses that would otherwise contaminate the air. Knowing when to replace them, however, is crucial to ensuring their continued performance and maintaining the integrity and safety of your operations. This guide will give insight into how often you should change HEPA filters for cleanrooms and what to look for to retain their effectiveness.
How Often Should You Change Your Cleanroom’s HEPA Filter?
When HEPA filters are performing as they should, they successfully manage air cleanliness and contamination levels in cleanrooms and pass thru boxes while helping your systems run more efficiently and cost-effectively. Checking your filters regularly will help ensure optimal filtration and functionality.
Companies often advise changing your HEPA filters once every three to five years, on average. However, it really depends on the use of your cleanroom. If your systems are operating around the clock, for example, you’ll likely have to replace your filter more frequently than a cleanroom that runs only a few days each week. The level of contamination in the air and the class of the cleanroom can also impact replacement frequency.
While they don’t stipulate the exact lifecycle of a HEPA filter, the International Organization for Standardization (ISO) 14644-3 guidelines and Good Manufacturing Practices (GMP) do require that you leak-test your filters periodically. Ideally, this should be done by an independent professional at a frequency of every six months to one year at a minimum. ISO 1-5 zones require these tests every six months, while in ISO 6-9 environments, annual leak testing is acceptable. GMP simply requires that filters be free of leaks. Should your filter fail to pass the test or if the industry professional observes any issues, it’s time to replace the HEPA filter.
However, there are additional factors to keep in mind when deciding how frequently to change the HEPA filter, such as filter load and pressure drop. As particulate matter builds up on a HEPA filter, its resistance to airflow increases. This can result in premature failure, allowing contaminants to enter the space. A clogged or damaged filter can also lead to pressure drop, decreasing airflow. If your ventilation system experiences excessive pressure drop, it will have to run at greater speeds to retain optimal rates of air exchange, increasing both energy consumption and costs in your operation. Should this occur, you can replace your filter for better performance and cost-efficiency and to put less strain on your system.
Extending Your HEPA Filter’s Lifespan
The factors that impact the lifespan of HEPA room air filters include:
- Volume of external air you’re filtering
- Level of contamination in that external air
- Any prefiltration methods and their level of effectiveness
- Volume of filtered recirculated air
- Aerosol challenge exposure duration and frequency
Proactive measures in the form of regular inspections and preventive or condition-based maintenance (CBM) will help to extend the life and ensure the efficiency of a HEPA filter. For example, through recent advancements in technology, manufacturers can monitor their equipment’s condition using sensors, carrying out maintenance only when the sensors signify there’s an issue or change in performance.
The proactive approach also benefits companies with custom-made filters, as these products typically take longer to arrive. If you use customized HEPA filters, periodic inspections will help you plan ahead for reorders.
Liberty Industries: The Contamination Control Experts
Liberty Industries, Inc. manufactures and distributes cleanroom and contamination control equipment and supplies for customers in industries such as healthcare, pharmaceuticals, cannabis production, aerospace, automotive, industrial, government, and academia. Since 1953, we’ve provided our clients with turnkey solutions and well-honed capabilities ranging from cleanroom design and construction to particle counter, airflow equipment, and even protective garb manufacturing.
Whether you need HEPA filters, modular cleanrooms, air showers, laminar flow equipment, Tacky Mats®, or another of our quality product offerings, our engineers can help you customize it to meet your unique needs. Contact us today for more information on how Liberty Industries can support your cleanroom operations.
