Electrostatic air cleaners (sometimes known as electrostatic precipitators) are highly efficient filtration devices that use electrostatic attraction to remove fine particulate matter such as dust and cigarette smoke from the air. Electrostatic air cleaners ionize (or electrically charge) particles as incoming air is drawn over an electronic cell. The charged particles are then attracted to and trapped by a series of flat collector plates that are oppositely charged, with the particles literally “sticking” to the collection plates until they are manually removed.
Electrostatic air cleaners have two main drawbacks. First, they can produce ozone – a known lung irritant and asthma trigger. While many units produce negligible levels of ozone, there are some brands and models on the market that exceed government safety standards. They may also produce ultra-fine particles from the reaction of the ozone with indoor chemicals (e.g., those from household cleaning products, paints, flooring or carpeting) that some people are sensitive to.
The second major drawback is the need to constantly wash the collector plates. The ability of the plates to attract particles decreases rapidly as they fill up, so they need to be cleaned frequently (e.g., weekly or even daily, depending on the levels of contaminants in the room) to keep the air cleaner working at maximum efficiency. Because the particles bond so tightly to the metal plates, vigorous scrubbing may be necessary to clean them completely, while the close spacing of the fixed plates in some models can make them a challenge to maintain. However, the upside of electrostatic cleaners is that there are no expensive filters to replace.
The efficiency of air purifiers using this technology exclusively to clean the air depends greatly on factors such as the size of the collection plates, how much power is being produced in the electric field, the airflow rate through the machine, and most importantly, the owner’s willingness to clean the collection plates frequently. Although highly effective for the filtration of particles, caution should be used in purchasing electrostatic air cleaners because of the possible generation of ozone and the intensive maintenance requirements.
Some air purifier manufacturers have combined the highly effective air cleaning elements of electrostatic technology with other proven air cleaning technologies such as HEPA filtration to produce air purification systems that can achieve better results than either technology alone. Such is the case with Blueair, who uses an innovative encapsulated ion particle charging chamber to apply a negative charge to incoming contaminants, thus ensuring that they adhere effortlessly to the advanced filtration media. This exclusive HEPASilent™ technology, featured in all full-size Blueair models, is not only incredibly quiet and simple to maintain, but effectively removes airborne particles down to 0.1 microns with a guaranteed minimum effectiveness of 99.97%.
Best of all, this amazing level of filtration is achieved with zero ozone emission! Blueair air purifiers use a very weak electrical current to minimize ozone production and a fully-sealed steel housing chamber to contain the minute amount that is produced. In fact, independent laboratory testing confirms that ozone concentration in the air coming out of a Blueair air purifier is actually lower than that in the incoming air.