Air Filters

• 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 which 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.

Air Filters - Air Filter Technologies and Terminologies