Air cleaners use a variety of filtering technologies to remove airborne
contaminants and odors from the air.
HEPA filters, or High Efficiency Particulate Air filters,
are designed to remove 99.97% of all airborne particles
0.3 microns or larger from the air that passes through the filter.
ULPA filters, or Ultra-Low Penetration Air filters, are designed
to remove 99.999% of all 0.3 micron airborne particles from the air
that passes through the filter.
Electrostatic filters have a static charge on the filter to allow
airborne particles to "stick" to the filter, just as static-charged
clothing sticks together.
Electrostatic precipitators create opposite charges on the metal
wires or plates in a precipitator assembly. They attract airborne
particles to the plate or grid wire that contains an opposite charge.
The assembly can be washed and reused.
Ionizers emit a small charge into the air stream, which causes
particles to adhere to the filter or other surfaces by a magnetic-like
attraction. This charge causes the particles to stick together,
making them larger. These larger airborne particles are easier
to capture as they pass through the filter.
Ozone air cleaners introduce small quantities of ozone into the
air to reduce airborne pollutants.
Carbon filters capture large airborne particles and help reduce
unpleasant odors. They should be replaced every 3 to 6 months,
depending on usage.
Washable foam filters help capture large airborne particles.
Foam air filters should be periodically removed from the air cleaner,
washed in warm, soapy water, then rinsed, drip-dried thoroughly, and
re-installed in the air cleaner.