Air purifiers are home appliances that remove contaminants from the air. They are a great addition to your home if you suffer from allergies or asthma and are also great at reducing or eliminating second hand tobacco smoke. They also reduce the need for frequent room and area cleaning.
The biggest reason air purifiers are needed in homes is to improve indoor air quality. The Environmental Protection Agency has reported that indoor air pollution levels can be up to 5 times higher than the pollution levels outside. The average American only spends about 10% of their time outside. Common indoor allergens and pollutants include:
- One of the smallest allergen particles, second hand tobacco smoke, is linked to various health issues such as asthma.
- Asthmatic and allergic reactions in people who are allergic to cats and dogs can be caused by animal dander. This allergen is created from dander flakes shed by pets and remains in your home long after a pet has left.
- Each time a door or window is opened, millions of pollen particles enter your home. Pollen is created by trees, flowers and grass.
- Showers, kitchens and basements are breeding grounds for mold and mildew. These plant spores can be found anywhere there is a supply of water and warm, humid climates.
The way air purifiers work is that they draw air from the room with a fan, clean the air and send it back out into the room. There are a few different purification types that air purifiers use to clean the air.
There is adsorption, which uses activated carbon or zeolite to remove chemicals, tobacco smoke and odors. Activated carbon is a porous material that adsorbs volatile chemicals on a molecular basis but does not remove larger particles. Zeolite is a microporous minerals mineral that is also used to adsorb chemicals.
Mechanical filtering is another purification type. This includes HEPA filters which remove 99.97% of 0.3 micrometer particles.
The electrostatic or electronic purification type uses charged plates to give particles a charge of one polarity and a set of collecting grids or plates that have the opposite electronic charge. Air purifiers that use this technology are called ionizers and they produce trace amounts of ozone.
There are also air purifiers that use ultraviolet light (UV) to clean the air. UV light kills microorganisms like bacteria and mold spores. This technology is always used in conjunction with other purification technologies.
One ultraviolet light purification type is ultraviolet germicidal irradiation (UVGI). Air that passes UV lamps is sterilized via forced air and microorganisms are broken down. Another is photocatalytic oxidation (PCO). This technology uses short-wave ultraviolet light to kill 99.9% of bacteria and viruses.
The last type of purification technology is an ozone generator. These air purifiers are designed to produce large amounts of ozone. Ozone is a strong oxidant gas which can oxidize many other chemicals and should be used in unoccupied rooms.
