Air cleaners are enhanced filtration systems that can be installed in your central heating and cooling system to remove greater quantities of dirt, dust and pollutants from the air circulating throughout your home. Some air cleaners are so efficient that they even remove gases, smoke, viruses and influenza.
Air cleaners can be divided into three major catrgories: Passive media filters, electronic air cleaners, and HEPA filters.
Passive Media Air Cleaners
Passive media filters are enhanced filter surface area cleaners that remove small particles of dust, dirt and pollutants down to .3 microns in size and need to have a disposable filter cartridge replaced once every 12 months. Media filters come in different MERV ratings. MERV stands for Minimum Efficiency Reporting Value. The higher the MERV rating, the better the the filter is at removing particles from the air. These filters do an excellent job of removing excess dust and dirt and in keeping your air conditioner, coil and equipment clean for many years.
Electronic Air Cleaners
Electronic air cleaners (or electrostatic precipitators) use a high voltage electrical field to charge the particles of dirt and dust, then collect the dirt and dust on an oppositely-charged metal collector cell or plate. While this air cleaner needs no replacement filter, it has to be washed and cleaned 3 to 4 times a year to remain effective. One such product, the Aprilaire 5000, combines the replaceable media filter with the electronic collector cell and is in effect 2 air cleaners in one. It not only needs washing and cleaning but also a once a year replaceable filter.
HEPA Air Filters
HEPA and HEPA-type filters remove microscopic particles of dust and dirt down to .1 micron in size and can also stop smoke and viruses along with gases. HEPA is an abbreviation for High Efficiency Particulate Arrestance and is used to describe filters that are 99.7% effective in the removal of dirt and dust at .1 micron in size.
There are many differnt types of HEPA filters, with some needing replacement filter cartridges annually, and some being able to be washed and cleaned for reuse for a number of years. Some HEPA filters do 100% of the filtration and are the only filter used on your heating & cooling system, while others use the principle of bypass filtration and are used in conjunction with a media filter or an electronic filter.
