The aim of keeping an air purifier is to free the air from all of the contaminants. When environmental researchers highlighted the fact that the indoor air is dirtier than the outdoor air, the popularity and the demand for air purifiers soared. Air purifiers will be helpful to persons suffering from allergies and asthma and to those who want to reduce the risk of passive smoking.

Air purifiers on the market use various different techniques for purification of the air. Electrostatic charges, ionizers, charcoal and absorbents are some of the methods used to purify the air. Germicidal ultra violet light is also used for this purpose. Find more info at www.onlyairpurifiers.info

Visual appeal, noise level and filter replacement frequency are some of the factors to be taken into account when selecting an air purifier. Filters also come in many different varieties. Some of them can be cleaned by hand, water or by vacuuming. Some of these filters need to be replaced within months depending upon the usage.

Air purifiers filtering out 99.97 percent of particles of 0.3 micrometers in the air are set as the best air purifier. These types of purifiers are very expensive.

The Association of Home Appliance Manufactures (AHAM) is the agency rating the performance of various air purifiers. The indicator used is the clean air delivery rating. There is some controversy over the claim involving ionic air purifiers since these machines generate the pollutant ozone. High concentration of ozone emitted by the air purifiers can pose some threat to health.

According to the American Lung Association, the effectiveness of an air purifier depends on the unit's efficiency and the amount of air drawn through it. Look into the type of pollutants it will capture and the percentage it captures. Select a device that circulates air many times an hour. .

Besides air circulation, ensure to consider other factors such as:

- Can it move air from all corners of the room

- Size of the room

- Whether the air purifier is meant for any specific problem such as smoke or pollen.

- Adaptability to the change in needs.

Cost of an air purifier and its efficiency are not related. Recurring costs are also to be taken into account. The energy needed to run the purifier will make quite a lot of difference to the power bill. Noise can be a big problem if the air purifier is meant for use in a bedroom or in the family room, since many air purifiers use loud motors to draw air through filters.