HEPA Filter Technology
HEPA Filter Technology
About HEPA
HEPA stands for high efficiency particulate air filter and describes a filter that can remove at least 99.97% of airborne particles 0.3 microns in diameter. Particles of this size are used to evaluate the performance of a HEPA filter, because they are among the most difficult to remove. HEPA filters are considered the safest and most efficient method to treat airborne particles.
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 other materials from the air. They have been proven to be very effective at removing dust, pollen, mold, dust mites, bacteria, and other allergens from the air. Another benefit to HEPA air purifiers are that once the particles are captured in the filter, 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 they 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 can last 2-5 years.
HEPA Air Purifier Drawbacks
Like any air cleaner technology, standard HEPA air purifiers do have their drawbacks, although they are minor. First, standard HEPA filters typically capture 99.97% pollutants that are larger 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. In most instances, a carbon filter is used in conjunction with the HEPA filter in order to filter the pollutants, such as odors and gases, that the HEPA filter cannot filter. --Air-Purifiers-101
However, their are other types of HEPA filters that are rated at 99.99% efficient at removing airborne particles 0.3 microns in diameter like the Super HEPA used in Airpura's 614 series. Also AllerAir's Micro-HEPA particle filters are manufactured with a material that is 99% efficient at removing airborne particles 0.1 microns in diameter. -- Electrocorp
Conclusion
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.