What is a HEPA Filter and How Does it Work?

It's important to note that a HEPA vacuum is designed to offer HEPA performance and can be a bagged or bagless model. In other words, it's not the bag that makes a vacuum cleaner HEPA. It's also important to understand that just using a HEPA-type bag or adding a HEPA filter to a standard vacuum doesn't mean you're going to get real HEPA performance. A HEPA filter is an air filter designed to capture particles of all sizes, from the smallest of viruses to larger dust particles.

HEPA stands for High Efficiency Particulate Air, and these filters are used in many different applications, from air purifiers to vacuum cleaners. HEPA vacuums are sealed and have special filters that clean all the air that comes out of the vacuum. Unlike sieves or membrane filters, through which particles smaller than openings or pores can pass through, HEPA filters are designed for a variety of particle sizes. The high-quality HEPA filter of the second phase removes the finer particles that escape from the prefilter.

The idea behind the development of the HEPA filter was born from the gas masks worn by soldiers fighting in World War II. True HEPA filters have an assigned serial number and have been shown to trap at least 99.97 percent of 0.3 micron particles. For a vacuum's HEPA filter to be effective, the vacuum must be designed so that all air entering the machine is expelled through the filter, without any air passing through it. However, just because the filter or vacuum bag says HEPA doesn't mean you're getting true HEPA performance.With the ability to trap 99.97% of airborne particulates, HEPA filters are a well-known solution for preventing allergies and relieving indoor allergies. For more than 80 years, HEPA filter technology has played a critical role in removing harmful airborne contaminants from the air.

Common standards require that a HEPA air filter be removed from the air that passes through it by at least 99.95% (ISO, European standard) or 99.97% (ASME, U. S.). Since then, HEPA filter technology has played a critical role in protecting Americans from pollutants in the air they breathe.

HEPA filters

are essential to prevent the spread of airborne bacterial and viral organisms and, therefore, infections. Because of the added density of an authentic HEPA filter, HEPA vacuums require more powerful motors to provide adequate cleaning power.

In fact, HEPA filters are more efficient at capturing smaller particles, such as those the size of viruses (which on average are 0.1 microns), due to the behavior of these smaller particles (see a NASA study). HEPA is a type of filter that can trap a lot of very small particles that other vacuums would simply recirculate to your home air.