Air Systems Cleaning Specialist (ASCS) Practice Exam

HEPA filters, or High-Efficiency Particulate Air filters, are specifically designed to trap a vast majority of particles that are 0.3 microns in size. These filters are highly effective at removing dust, pollen, mold spores, pet dander, and even some bacteria and viruses from the air. This high level of efficiency makes HEPA filters a standard choice in applications requiring superior air quality, such as hospitals, clean rooms, and residential settings where allergy and asthma concerns are prevalent.

Unlike other types of filters, HEPA filters are rigorously tested to ensure they meet strict standards, achieving a minimum efficiency of 99.97% in capturing particles. Other filters, such as electrostatic, fiberglass, or charcoal filters, do serve important functions in air filtration but typically do not match the particle removal efficacy of HEPA filters. For instance, electrostatic filters use an electrical charge to capture particles, while fiberglass filters generally allow smaller particles to pass through, and charcoal filters primarily target odors and gases rather than particulates. Therefore, HEPA filters are distinctly acknowledged for their capability to deliver high-efficiency filtration, warranting their common use in high-filtration systems.