Air purifier

From ArticleWorld

An air purifier is a machine or device that is used to remove particulate debris, allergens and bacteria from the air. There are many kinds of air purifiers that are designed to improve health by reducing the numbers of pathogens or allergens in the air.

Types

There are mechanical air filters that push air via suction through a fibrous filter. Furnaces have that type of filter. Charcoal filters use activated charcoal that absorbs or binds to materials as air passes through it. Ionizers create negatively charged particles that attract or destroy particles, pathogens or allergens in the air. UV light or radiation can “filter” air by killing pathogens that can’t survive irradiation or the UV wavelength of light. Filters come in different sizes for rooms or areas of different dimensions.

Consumer Issues

Air purifiers have different regulations or standards. The Department of Energy has standards for HEPA-like filters. HEPA is actually a corporation that makes various kinds of filters. The Department of Energy requires that HEPA-like filters filter at least 99.97% of pollutants greater than 0.3 micrometers. The Clean Air Delivery Rating (CADR) is a standard developed by the Association of Home Appliance Manufacturers. The higher the rating, the better is the function of the filter.

Some consumer groups doubt the safety and effectiveness of ionizing air filters. They purify air by creating negatively charged gaseous and solid particles. The charged particles are supposed to attract to something heavier and fall out of the air. This usually means that dirt collects in and on the ionizer, rendering it less effective. In addition, ionizing air filters create small particles of toxic ozone in the air.