HEPA Air Purifiers - Unparalleled Particulate Abatement
HEPA Filters, or High Efficiency Particulate Air Filters, were originally designed in the 1940s to prevent the spread of radioactive contaminants. These filters were eventually commercialized in the 1950s, and the original term became a registered trademark and generic term used to describe highly efficient air filters. Over time, higher demands for air quality in technology industries such as nuclear power, aerospace, and hospitals prompted the establishment of guidelines for HEPA filters.
Can Filter Down to 0.3 Microns
To be considered a True HEPA filter, a filter must be capable of removing at least 99.97% of airborne particulates as large as 0.3 microns, which is 1/75,000 of an inch or 1/300 the diameter of a human hair. Particles of this size are the most difficult to remove, and therefore, air purifiers utilizing HEPA filtration are considered the most effective at particle control.
What are HEPA Filters?
HEPA filters are composed of a mat of randomly arranged fibers that target and trap small pollutants by one of these three mechanisms:
- Interception: This occurs when particles follow a line of flow in the airstream within one radius of a fiber and stick to it.
- Impaction: This occurs when larger particles are unable to avoid fibers and are forced to imbed in one, which also increases with diminishing fiber separation and higher air flow velocity.
- Diffusion: This occurs when an enhancing mechanism is the result of the collision with gas molecules by the smallest particles, which are then impeded and delayed in their path through the fiber.
Other Benefits of HEPA Filtration
Not only are HEPA Air Purifiers excellent at controlling pollutants in the home, HEPA filtration is also one of the only government-approved methods for particulate control. In fact, the Centers for Disease Control recognize that hospital air purification systems with HEPA filters play a crucial role in airborne infection control of diseases such as influenza, tuberculosis, and SARS.
In addition, immediately after the September 11 attacks, the CDC instituted the use of HEPA filters in post offices to address the increased risk of anthrax. Therefore, because of HEPA filters' amazing air purification abilities, they are often used in conjunction with UV sterilization in hospitals and medical facilities, where they provide a very high level of protection against airborne disease transmission.
When choosing a HEPA air purifier, select one that uses a True HEPA filter with 99.97% or greater efficiency. It should also be noted that because HEPA air purifiers circulate contaminated air through filters, they can generate noise. If this is a concern, ionizers or ozone air purifiers may be more suitable.
Hence, it is easy to see why the best air purifiers utilize HEPA technology. Perfect for any air purification concern, HEPA filtration is clearly the most effective method of particulate control.