HEPA filters are widely believed to degrade over time, both during proper storage and during normal operational service. However, the exact rate of degradation is unknown. These filters are designed to capture fine particles such as smoke, pollen, mold fragments, and other debris from the air. As the filter fibers become clogged, the purifier will experience a decrease in airflow and fewer particles will be filtered out.
Cleaning a HEPA filter instead of replacing it is a common question, but without a solid history of testing, it's not clear how that cleaning can affect its performance. HEPA filters are made from a variety of materials, such as thick glass fibers, coated animal hair, plant fibers, synthetic fibers (such as polyester or nylon), synthetic foams, metallic wool or expanded metals and sheets. To meet the HEPA standard, it is estimated that a filter must remove 99.97 percent of particles that are 0.3 microns (or micrometers) in size from passing air. You can rinse the filter with water, wipe off excess dust with a tap, or remove dust with a vacuum, but this can potentially damage the fiber mesh that allows the filter to capture particles from the air. Effluent Management (EM) is coordinating a 10-year effort to collect and analyze the lifespan of HEPA filters compared to other requirements of the competition. Some harmful contaminants, such as most airborne chemicals, are much smaller than what a HEPA filter can trap.
As there are no official standards for cleanable HEPA filters, there are no defined terms for the types of cleanable filters available. The lifespan of HEPA filters was determined through an analysis of several research studies conducted by Bergman at the Lawrence Livermore National Laboratory (LLNL). Initially, HEPA filters were used in industrial and research facilities because they were specifically developed to remove radioactive particles from the air in nuclear test laboratories. However, there is no standard for washable HEPA filters and there have been no public studies to prove the effectiveness of these filters once washed. In addition to HEPA filters, there are several air purification technologies available that you can use to improve air quality in your home. The PECO-HEPA Tri-Power filter combines the efficiency of HEPA particles with the destruction of the PECO, reducing the chances of mold or pollen being released into the air.
While HEPA filters are intended to remove particles from the air and improve indoor air quality, they can be expensive, especially when considering ongoing replacement costs. Overall, it is important to understand that HEPA filters do degrade over time and need to be replaced regularly in order to maintain optimal performance. Cleaning them instead of replacing them may be an option for some people but it is important to understand that this could potentially reduce their effectiveness. It is also important to consider other air purification technologies that may be more effective and cost-efficient than HEPA filters.
