HEPA air purifiers are one of the most popular and effective technologies for cleaning air available today
HEPA air purifiers are those that cause air to pass through a specially-designed filter called HEPA, which stands for High Efficiency Particulate Air. These HEPA air purifiers are designed to remove 99.97% of all pollutants that are 0.3 microns or larger. For reference, 1 micron is 1/100th the width of a human hair!
HEPA filtration technology was developed by the US Atomic Energy Commission to filter our radioactive "dust" and materials from the air. They have been proven to be very effective at removing dust, pollen, mold, dust mites, bacteria, and other allergens. Another benefit to HEPA air purifiers is that once the particles are "captured", they are not released again back into the air.
HEPA air filters look like most other air filters you've seen, many have a pleated media, separators, wet laid filter medium, edge seal, a sealant and are contained in a rigid frame. By their nature, HEPA air purifiers do not lose their efficiency over time. Although, they do have the potential of becoming clogged and blocking airflow.
If you are considering purchasing an air purifier that uses HEPA technology, make sure the unit has a prefilter. A prefilter filters out larger particles (1 micron and larger) before they reach the HEPA filter. This extends the life of the HEPA air purifier, which can be expensive. Most HEPA filters will last about 2 years.
HEPA air purifier drawbacks
Like any air cleaner technology, HEPA air purifiers do have their drawbacks, although they are minor. First, HEPA filters cannot capture pollutants that are smaller than 0.3 microns. Things like viruses, odors, and gas molecules are not effectively treated. Also, because air must pass through the filter, it can be difficult to clean a very large room with a HEPA filter.
Overall, HEPA air purifiers are very effective at what they are designed to do; which is to clean your air. These types of purifiers have become very popular and are being used increasingly in hospitals and sensitive-equipment manufacturing plants. Many experts in the field of air purification prefer HEPA technology over all others. HEPA filters work best in conjunction with other filters.