Home air purifiers

Home Air Purifiers are used to maintain the house free of airborne pollutants. These are very useful for asthma, smoke, mold, pet dander and other home pollutants. This device must be ozone-free and should be able to deal with allergy and asthma symptoms, MCS (Multiple Chemical Sensitivity) and air quality problems like cigarette smoke, construction dust and pollution.

The Technology

The main procedure is to draw air from the room using a fan, then to clean the air and propel it back in the room. There are various ways of cleaning. The first is that of adsorption. A media like zeolite or activated carbon is used. The air comes in contact with a large surface area as the above media are porous. When the chemical contaminates touch the media, they combine with the media and thus are removed from the air flow. Chemicals. Tobacco smoke and odors are effectively removed but particles cannot be separated. The second is that of mechanical filtering. A very fine screen is employed to remove the particles. The HEPA filter can segregate particles that are 0.3 microns in dimension.

Thus, HEPA technology can remove pollen grains and mold spores, but has minimal effect on chemicals. Hence, this technology is combined with the absorption filter. The third is the electrostatic or electronic technology. In this charged plates are used. The particles are given a charge of one polarity. The set of collecting plates or grids have the opposite polarity. As the air containing the charged particles reaches close to the collecting grid, the particles are attracted towards it due to opposite polarity.

When the particles segregate on this grid, the charging voltage starts to arc and gives rise to a popping sound. This is an indicator that the air cleaner plates must be cleaned. A unique technology is a combination of the HEPA and electronic. The electrostatic brushes charge the particles and then the air is mechanically filtered. So, HEPA with large holes can be used resulting in higher output. The use of Ultra-violet light is not a cleaning technology. The UV light kills the microorganism like bacteria and mold spores. This is combined with other technologies.

Advantages and Disadvantages

HEPA (High Efficiency Particulate Arresting) filter technology is the most ideal for the air purifiers. It can remove 99.97% of pollen and dust particles that pass through it. To maintain the efficiency, the filters must be changed. The Electrostatic or Electronic systems having charged plates put aside the expenditure of replacing filters. However, the plates have to be washed. Both these technologies are successful in removing particles, but chemicals and odors cannot be removed. To deal with these two, the air purifiers should have activated carbon in some form. Sometimes UV is put into use with a HEPA filter to eradicate micro-organisms.

Treatment of diseases

In case of asthma, the cause may be a particle like a pollen grain or a chemical or an odor. So, both mechanical and adsorption technology must be employed. For MCS, the constant irritant enhances the sensitivity. So, adsorption has to be put in practice.

Home air purifiers

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