Air purifier

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An air purifier is a device which aims to free air from contaminants. The popularity of air purifiers spur from the results from environment researches which claim that the air inside homes are dirtier than the air outside of homes. Air purifiers are particularly beneficial for allergy sufferers and asthmatics or those who wish to reduce second-hand smoke.

Contents

1 Use of purifiers
2 Purifying techniques
3 Consumer concerns
4 \"Pure\" controversy
5 See also
6 External links

Use of purifiers

Allergy-inducing culprits are known as allergens. Allergens can come in the form of dust or pollen as well as pet dander and mold spores. Hazardous smoke particles and airborne gases may also find their way into homes and bedrooms. Because of the significant amount of time most people spend indoors, many wish to ensure air purity.

Purifying techniques

Various techniques are used in air purifiers in the current market to accomplish indoor air purification. These techniques include mechanical filters, absorbents like charcoal, and electrostatic charges or ionizers. Additional setups include germicidal UV light and the emission of ions into the air to react with contaminants and making them harmless enough to breathe.

Consumer concerns

When selecting air purifiers, consumers are influenced by several factors, including visual appeal, noise level, and frequency of filter replacement. There are many different types of filters, some can be cleaned by water, by hand or by vacuuming while others need to be replaced within a few months or a few years.

The most popular sort of filters for air purifiers is the HEPA filter. The Department of Energy has rigid requirements manufacturers must pass to meet HEPA requirements. Products that say "HEPA-type" or "HEPA-like" may not meet these requirements. HEPA requirements necessitate being able to filter out 99.97% of pollutants in the air of 0.3 micrometres in size. While HEPA filters are extremely effective, they are also extremely expensive, and replacements can often cost nearly as much as the air purifier itself. For this reason, many air purifiers utilize both a HEPA filter and a less expensive "pre-filter" to reduce the frequency of HEPA filter replacement.

CADR, or Clean Air Delivery Rating, is a standardized indicator of how well a particular air purifier can function as compared to other air purifiers. The higher it is, the stronger the power of purification. CADRs are rated by AHAM, or the Association of Home Appliance Manufacturers, and are based on stringent requirements as produced by the association itself.

\"Pure\" controversy

As with all health-related appliances, there is some controversy surrounding the claims of certain companies, specifically involving ionic air purifiers. Particularly, these machines generate the pollutant ozone. Ozone from air purifiers can be dangerous in high concentrations.

External links

[DOE HEPA Filter Standards](pdf) HEPA filter specifications for DOE contractors
[AHAM] Association of Home Appliance Manufacturers (AHAM)
[Air Purifiers Review] Consumer Report's section on Air Purifiers
[link] EPA report on the effectiveness of ozone generators
[CADR.org] Information on Clean Air Delivery Rate by AHAM

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