Before getting into details about hepa air filters it is important to first answer a commonly asked question regarding the word HEPA. What does hepa stand for? HEPA is an acronym which stands for High Efficiency Particulate Arrestance. Another definition commonly used is High Efficient Particulate Air but this definition is less accurate and really doesn’t make much sense.
To qualify as a HEPA filter, the filter has to capture a minimum of 99.97% of all particles .3 microns in diameter. That is about 300 times smaller than the diameter of a human hair and smaller than we can see.
Hepa air filters are among the most efficient air conditioner filters available. At over 99 percent efficient, a hepa air filter will remove almost all allergens from the air that passes thorough your HVAC equipment. Hepa air filters remove dust mite particles, pet dander, pollen, mold spores and other household allergens.
Hepa air filters are commonly used in environments where very clean air is a must, such as clean rooms, hospital wards, surgical rooms and other places where maximum dust removal is very important. Hepa filters are also used in many other applications such as very efficient hepa vacuum cleaners and HEPA air cleaners and air purifiers.
One of the most efficient hepa type filters is the Hepa-Pure filter, available from RiteAir.com. Although not considered a "true" Hepa filter, it is rated at 99.97 percent efficient. These filters have 7 or 8 pleats per inch so there is more surface area to collect dust. A very important benefit of Hepa-Pure filters is that they can be cleaned several times to extend usable life.
These filters are not typically recommended for use in residential HVAC equipment. Before upgrading to one of these filters you should have your system checked by a contractor to make sure it will not cause problems with equipment operation.
A hepa air conditioner filter has the potential to provide relief for allergy and asthma sufferers because they trap mold, pet dander, pollen, bacteria and many other airborne particles. Use of these filters requires that you be very diligent with maintenance. This is important, to prevent problems that can arise from reduced air flow through an air conditioning system when they become dirty.
Some Details About How Hepa Filters Work
A hepa air filter is very similar in design to regular pleated air conditioner filters except for some very important differences. Hepa air filter material is different than that used in regular pleated air filters, and there are more pleats per inch of filter than in pleated filters. The material must be much denser to stop smaller particles.
The reason there are more pleats per inch of filter is to help reduce how frequently hepa air filters have to be cleaned or replaced. Having more pleats per inch enables the filter to remain in operation longer because dust tends to collect in the lowest point between the pleats. This means it will take longer for air flow to be reduced through the filter.
Don has been working in the HVAC industry for more than 25 years and shares his experience and knowledge on this site. You can also follow him on: