The Environmental Protection Agency has determined that almost 90% of the people spend their time indoors. This means that indoor air quality is much more important than outdoor air quality for most people.

HEPA (High Efficiency Particulate Air) filters are recommended by allergists and medical professionals for the removal of all dust particles in the size range of droplet nuclei from the air. The HEPA filter, a mechanical filter, was developed by the Atomic Energy Commission of U.S.A. during World War II to prevent radioactive particles from escaping from plants and laboratories. Those initial HEPA air filters were very bulky compared to those that are produced today.

HEPA filters are able to trap 99.97% of particles having the size of 0.3 micron, including harmful fibers, dust, smoke, pet dander, and more. With the capacity to collect dirt particles, which are 1/300th the width of the human air, these filters have high resistance power and cannot be placed directly in heating or cooling systems.

These filters are used as the primary filtration systems for electronic clean room assembly, isolation wards, surgical theaters, bioengineering units, pharmaceutical processing units, and other places where the maximum removal of sub-micron particulate is required. They are also used in portable units to supplement a building