| An air purifier is an appliance used for cleaning air | | | | designated as HEPA, air purifiers must meet very |
| indoors and they are used in homes, commercial | | | | stringent requirements as laid down by the |
| buildings, industrial workplaces etc. The application | | | | Department of Energy. HEPA filters should |
| of air purifiers is usually in places which tend to | | | | remove at least 99.97 % of air borne particles of |
| have unhealthy air due to pets, molds, pollutants, | | | | 0.3 micron size at 85 liters per minute rate. |
| smoke or industrial work, hazardous materials etc. | | | | However HEPA filters are very expensive and |
| They are also popular in homes of allergic people | | | | replacing the filter in the purifier may cost as |
| and people with asthma who wish to keep the air | | | | much as the purifier itself. Further HEPA filters |
| healthy in their homes. They are also popular due | | | | cannot remove gases or odors from the air. For |
| to the fact that the air inside homes is less | | | | removing gases, absorbent types of purifiers are |
| healthy than the air outside. | | | | suitable. |
| Since people spend a significant amount of time | | | | Ozone |
| indoors having an air purifier is healthy. | | | | Some Ionic purifiers produce ozone in the |
| Allergic applications | | | | delivered air. Ozone can be dangerous at higher |
| Air purifiers are most popular for asthmatic and | | | | concentration, which is the cause of a |
| allergic people and they work by keeping allergens | | | | controversy. However ionic purifiers are |
| and triggers out of the air in homes. Allergens or | | | | associated with healthy air environments such as |
| triggers can be dust, pollen, mold spores, fungus, | | | | waterfalls, mountains etc, since these places have |
| pet hair, smoke particles, airborne gases etc. | | | | a negative ion concentration as in ionic types. An |
| Functioning | | | | ionic air purifier in conjunction with an air filtration |
| There are various techniques for air purification | | | | system is suited for most purposes. |
| like absorbents, ionizers, mechanical filters etc. | | | | What to look for |
| Absorbents can be in the form of activated | | | | Customers usually look for aesthetic appeal, noise |
| charcoal and ionizers can be in the form of | | | | levels, size of the equipment, frequency of filter |
| electrostatic chargers. Some have additional | | | | replacement, electricity consumption, air delivery |
| systems like germ killing UV light, ionizer for | | | | rate etc. Most of the filters can be cleaned easily |
| neutralizing contaminants. | | | | by vacuuming, by water or by hand. The filters |
| HEPA filters | | | | may need replacement anywhere between |
| HEPA is an acronym for High Efficiency Particulate | | | | months to a few years depending upon the type |
| Air. HEPA filters are very popular. Before being | | | | of air purifier. |