Air purifier

An air purifier or air cleaner is a device which removes contaminants from the air in a room. These devices are commonly marketed as being beneficial to allergy sufferers and asthmatics, and at reducing or eliminating second-hand tobacco smoke. The commercially graded air purifiers are manufactured as either small stand-alone units or larger units that can be affixed to an air handler unit (AHU) or to an HVAC unit found in the medical, industrial, and commercial industries. Air purifiers may also be used in industry to remove impurities such as CO₂ from air before processing. Pressure swing adsorbers or other adsorption techniques are typically used for this.

Dust, pollen, pet dander, mold spores, and dust mite feces can act as allergens, triggering allergies in sensitive people. Smoke particles and volatile organic compounds (VOCs) can pose a risk to health. Exposure to various components such as VOCs increases the likelihood of experiencing symptoms of sick building syndrome. Air purifiers are becoming increasingly capable of capturing a greater number of bacterial, virus, and DNA damaging particulates.

Several different processes of varying effectiveness can be used to purify air.

Other aspects of air cleaners are hazardous gaseous by-products, noise level, frequency of filter replacement, electrical consumption, and visual appeal. Ozone production is typical for air ionizing purifiers. Although high concentration of ozone is dangerous, most air ionizers produce low amounts (< 0.05 ppm). The noise level of a purifier can be obtained through a customer service department and is usually reported in decibels (dB). The noise levels for most purifiers are low compared to many other home appliances. Frequency of filter replacement and electrical consumption are the major operation costs for any purifier. There are many types of filters; some can be cleaned by water, by hand or by vacuum cleaner, while others need to be replaced every few months or years. In the United States, some purifiers are certified as Energy Star and are energy efficient.

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