HEPA Filters

HEPA Filters

Pleated Filters

HVAC Filters

One of the acronym used for HEPA filter is high efficiency particulate air filter. HEPA filter is highly efficient air filter used for filtration of small particles. This filter can remove at least 99.97% of airborne contaminants of 0.3 micrometers (µm) in size. More larger or smaller particles are filtered with higher efficiency. HEPA filters are manufactured in different efficiencies, depending upon the need, ranging from 95.0 % to 99.97%. Found in several equipments and appliances like vacuum cleaners, air cleaners etc., these filters are very efficient in removing severe harmful particles such as dust, dust mites, mold spores, pet dander and other irritating allergens.

HEPA Filters Components :

HEPA filters are fabricated from the following components :

• Filter: The filter is made up of either borosilicate glass fiber or plastic fiber which is bound by acrylic binder to render additional strength, up to 5%. HEPA filter can collect the particles of size up to 0.3 microns in diameter.
  
• Case: It comprises plastic case, made up from high-impact polyvinyl chloride, polystyrene, high-density polypropylene or polyethylene.
  
• Electric fan: Its function is to induce air flow through the filter.
  

Function of HEPA Filters

HEPA filters are fabricated to target smaller particles and contaminants, by any one of three mechanisms :

• Interception: In this process, particles follow a line of flow in the air stream available with in one radius of fiber and fixed to it.
  
• Impaction: Larger particles are forced to embed in one of the curving contours of air stream which increases air flow velocity and lowers the fiber separation.
  
• Diffusion: This mechanism is the result of collision gas molecules by the smallest particles, particularly those below 0.1 µm in diameter. Similar to Brownian motion, this process increases the probability that particles will be stopped by either interception or impaction, diffusion process is dominant at lower air flow velocities.
  

HEPA Filters Applications :

HEPA filters are used in wide number of industrial and other commercial applications. Some of them are :

• Nuclear industry: HEPA filters are used to remove nuclear emissions and radiations from the air, which are very dangerous for health. These filters must be appropriately installed in frame or filter housing to achieve best results.
  
• Pharmaceutical Industry: They are highly used in this field. The usage of HEPA filters creates a sterilized environment in pharmaceutical organization. Researchers and scientists continuously work to develop new technologies to fight with the dangerous diseases. Thus, in this process they have to work with hazardous items like AIDS virus, TB virus, E. Coli bacteria, and other deadly viruses. Hence, HEPA filtration is very important for their health and hygiene.
  
• Electronic Industry: Usually in the manufacturing units, HEPA filters are used to provide a clean room where the amount of particulates should be as less as possible. The fabrication of computer hard drives, motherboards, computer chips, cellular phone components and other electronic components require highly clean and dust free rooms to ensure safe and quality products.
  
• Aerospace industry: The construction of sophisticated parts and other component of the planes like space shuttles etc. require safe and clean surroundings. Their performance can be affected by the presence of minute dust and other pollutants, thus HEPA filters provide hygienic and clean surroundings.