Many people mistakenly assume that an air conditioning only controls the temperature of a living space. Air conditioning also involves the cleanliness of the air. Filtration is an excellent way to accomplish air cleaning and provide enhanced levels of comfort to a building's occupants. Continuous exposure to unfiltered air results in asthma, allergies, and breathing problems. Generally, air-conditioning systems include electronic air filters, which use electrical charges to attract and deposit 95% of household allergens and irritants to the human body. An electronic air cleaner is installed between the furnace and the air ducts to improve indoor air filtration throughout the home.
The air inside the home circulates through the cooling system, carrying millions of airborne particles with it. When this air is drawn into the system or device, a pre-filter in the electronic filter traps the majority of the allergens and irritants. Those particles that do pass through the pre-filter receive an electric charge inside the filter. Collector plates of the filter attract these particles and hold them until the cells are cleaned. Electronic air cleaners offer the optimum balance between air filtration and system pressure drop (air restriction).
There are two main types of electronic filters, namely electrostatic precipitators and charged media filters. In electrostatic precipitators, particles are collected on a series of charged plates, whereas in charged media filter devices, the particles are collected on the charged fibers of the filter. The most efficient filters are electrostatic precipitator, because in most of the electrostatic precipitators, the particles are deliberately ionized (charged) before the collection process, resulting in higher collection efficiency. These precipitators generate approximately 20,000 volts to give dust particles a static electric charge.
In order to determine the efficiency of an electronic air filter, there are two tests: the weight-arrestance test and the atmospheric dust-spot test. In the weight-arrestance test, the efficiency is tested on the basis of the weight of the dirt removed by the filter. However, this method will not give any idea as to the removal of smaller dirt particulate, which can be easily inhaled by lungs. The atmospheric dust-spot test determines a filter's ability to capture particles between 0.3 and 6 microns. Whatever test is used and whatever may be the type used, the electronic filter must be cleaned at least once in a month to improve the indoor air quality.
Or, browse through master article archive to see a listing of all main topics.