What is a high efficiency particulate air filter (HEPA)?

The difference between an authentic HEPA filter and a normal home furnace filter is huge. There are many filter products being sold in stores and on the internet which claim to be "HEPA type" or "HEPA rated" filters. What these descriptions are attempting to get around is the fact that there are very specific qualifications for HEPA which may prevent these less-than-qualified filters from being represented truly as "HEPA." To get to carry the name "HEPA filter", specific guidelines must be met as set forth by the U.S. Department of Energy. A true HEPA filter is able to remove 99.97% of all contaminates (.3 microns or larger) out of the air.  To show how small a micron actually is, the human hair is about 70 microns in diameter, so one can imagine how small the particles are that the HEPA filter is able to remove from the air.

True story: the first HEPA filter was created for the Manhattan Project in 1940 to help reduce the spread of airborne radioactive contaminates. These high efficiency particulate air filters did not actually become available for residential and commercial use until the 1950's. The HEPA filters have improved their methods of air purification throughout the years - today being almost exclusively used in the medical field.

There are some true HEPA products that are available for home use - but most of them are NOT the type of furnace or AC filters used in most residential homes. Unfortunately, HEPA filters restrict too much air to be used as a traditional furnace filter. Though the HEPA filter is extremely efficient, it requires a significant amount of air pressure to force air through the filter. A typical home furnace or AC system would not have enough air pressure to effectively use a HEPA filter.  Very little air would blow out of the registers.

In order to use a High Efficiency Particulate Air filter in residential homes one would need to install a separate HEPA filtration system. If you already do have an HEPA filtration system in your home you can inexpensively purchase HEPA Filter Replacements from Indoor Air Quality Source.