How Do Eltrostatic Air Cleaners Work?
Electrostatic air cleaners are a type of electronic air purifier that is generally used for whole-house or large-building applications. They work essentially as magnets by giving harmful or undesirable particles an electrical charge, which allows them to be trapped by a variety of methods. This type of air purification is generally considered to be less effective for allergy sufferers. Does this Spark an idea?
-
Electrostatic Precipitators
-
These are the most common type of electrostatic air cleaners, which work by drawing air through an ionizing chamber, where they are given an electrical charge. The particles are attracted to a series of metal plates, which hold an opposite charge, thereby trapping them. This type of air cleaner can trap particles as small as 0.1 micron, removing up to 95 percent of contaminants. An undesirable byproduct of these units is that they can produce ozone, sometimes in high amounts, which can be harmful to the environment.
Media Charged Filter
-
This type of air cleaner does not produce ozone, because it avoids metal-on-metal contact by using a filter, generally made of a fiberglass variation along with a carbon core to trap particles. The technology used here is similar, with the filter bearing a positive charge to attract contaminants, which naturally have a negative charge. Particles as small as 0.1 micron are also trapped by this technology, but as the filter ages, smaller contaminants begin to pass through, making the unit less efficient.
-
Negative Ion
-
The third type of electrostatic air purifier is also the most controversial, because particles are removed from the air but not from the room in which the cleaner is located. Negative ion units work by using a chemical injection technology that ionizes contaminants when they are drawn into the air cleaner. The air then leaves the cleaner with the particles attaching themselves to walls, carpeting, clothes and other surfaces that have a positive charge. The drawback to this method is that the particles can dislodge from the surfaces and ultimately return to the ambient air.
Hybrid Technology
-
Because electrostatic air cleaners are not efficient at removing allergens from the environment, some units use a hybrid technology involving HEPA (high efficiency particulate arresting) air filters. The accordionlike structure of HEPA filters trap dust mites, mold spores and pet dander, thus increasing efficiency of electrostatic units. They also reduce the presence of cigarette smoke, another irritant for many allergy sufferers.
Regular Maintenance
-
For electrostatic air cleaners to work properly, air filters must be changed regularly, as particles will collect on the surface, making the device less efficient. Most manufacturers recommend cleaning the filters at least once a month and completely replacing them on an annual basis. Those using metal plates to trap particles must also be cleaned regularly to maintain efficiency.
-
