Electrostatic Air Purifiers
What is an electrostatic air purifier?
Electrostatic precipitators (also called electronic filters) electrically charge airborne particles and then trap them on oppositely charged metal plates. They are available to be installed in central filtration systems and in portable units, usually with fans.
As with negative ion generators, they create negative ions within a space through which air flows, thus giving airborne particles a charge. The particles are then collected on an electrostatically charged panel filter or metal plate.
Electrostatic precipitators employ either a one or two-stage system, with the two-stage units being more effective than their one-stage counterparts. One stage systems use the same charged medium to charge the particles in the air and to collect them. Two stage systems use high-voltage electrodes or wires which place a charge on the incoming airborne particles, and then draws those particles between a series of oppositely charged metal plates which attract the particles from the air, causing them to precipitate onto the metal plates.
Collection efficiency of these units varies widely depending upon the area of the collecting plates, air flow rate, the strength of the electrical field, and the how often the collection plates are cleaned.
What contaminants do electrostatic precipitators remove?
Electrostatic precipitators offer fair filtration of general dust, particulate, and common allergens. However, it is important to note that these systems can lose their efficiency very rapidly as the collection plates get dirty. Furthermore, charged particles that are not captured on the collection grid may cling to objects in the home and soil them. Since HEPA filtration offers better performance without the concern over lost efficiency, we do not recommend the use of electrostatic precipitators in home air purifiers.
Note: these ratings apply to an electrostatic precipitator with clean collection media (effectiveness declines as media becomes contaminated).
Benefits of Electrostatic Precipitator Technology
- usually no filters to replace
Negatives of Electrostatic Precipitator Technology
- collection media/plates must be kept very clean to maintain effectiveness
- charged particles may collect on surfaces in the room and soil them
- some systems produce ozone, which is very toxic, as a bi-product of the charging process
What to Look for in an Electrostatic Precipitator Air Purifier
We do not recommend electrostatic precipitators. A HEPA filter is a more effective choice for residential and clinical air purification.