A high efficiency particulate air (HEPA) filter is a pleated device that can remove particles from surrounding air. A number of devices use these filters, such as air purifiers, which are designed to remove a host of particles and pollutants from the air in your home.
There is no federal certification or regulation for HEPA filters in the United States, but the Environmental Protection Agency offers some advice on how to choose efficient filters. Keep reading to learn some tips for choosing HEPA filters and how to find the best air purifier for your home.
HEPA filters remove tiny particles from dust, mold, pollen, bacteria, viruses, and more from the air. Thin glass fibers are randomly arranged into a dense, paperlike material that is folded into pleats to create the filter.
As air particles pass through these filters, pollutants are trapped in the fibers. Then, as larger particles stick to the filter, they keep other smaller particles from passing through. A HEPA filter can trap particles as small as 0.3 microns. For reference, the smallest thing the human eye can see is 25 microns, and a strand of hair is between 17 and 180 microns in diameter.
When placed into filtration systems like air cleaners and purifiers, HEPA filters can remove 99.97 percent of particles from the air. These filters were initially used in nuclear plants, but a host of new devices use this technology in products that can help clean the air in your home.
Types of filters
There are many kinds of air filters and air purification devices available for home use. HEPA filters can be used in cleaning devices, air filters, portable air cleaners, whole-home fan systems, heating and cooling units, and more. The goal is to filter tiny particles from the air as it passes through these devices.
HEPA filters aren’t the only way to do this, but they are recognized as highly effective, filtering some of the smallest particles from the air. Other examples of filters include:
- Ultra-HEPA filters or ULPA filters. These can trap up to 99.999 percent of particles 0.3 microns or smaller.
- Electrostatic filters. These trap particles using a small static charge, which help the particles stick to the filter.
- Electrostatic precipitators. These filters use metal plates or wires to attract particles with an opposite charge. They can often be washed and reused.
- Ionization. These filters rely on a small charge that emit a magnetic-like attraction to particles in the air. This type of filtration may release ozone gases and could cause …….