Air purifiers are designed to remove contaminants from the air, including allergens, dust, spores, pollen and more. Some purifiers also capture or reduce bacteria, viruses and odors. An air cleaner works by sucking in indoor air and passing it through a filter, which collects contaminants and returns clean air to the room. Depending on the type of air pollutant, an air purifier can be a great way to improve indoor air quality in an individual room or area.
The Environmental Protection Agency (EPA) states that these types of filters can remove 99.97%, or more, of particles in the air with a size of 0.3 microns, including dust, pollen, mold, and bacteria. Particles that are larger or smaller than that size are actually trapped with even greater efficiency. With the exception of these, and because of the risk of fungal growth in inexpensive HEPA filters that are not frequently replaced, air purifiers are generally safe. A small-scale study conducted in China found that air purifiers reduced fine particles in the air (dust, pollen, dander) and improved participants' blood pressure levels and lung function.
If you don't feel a positive effect on your allergy symptoms after using an air purifier for a month or two, you may want to reassess its location in the room (for example, moving it closer to your bed or sofa or moving it away from a door or window). Some filters are reusable and washable, but require meticulous maintenance, so they are not usually found in the most effective air purifiers. To eliminate smoke odor, look for an air purifier that contains an activated carbon filter. As air moves through the filter, contaminants and particles are captured, and clean air is expelled into the living space.
In fact, the EPA warns that the functionality of air purifiers is limited in terms of filtering gases and that you should replace filters frequently for optimal functionality, usually about every three months. Air purifiers usually consist of a filter, or several filters, and a fan that sucks in and circulates the air. You never know how polluted the air inside your home is until you use an air purifier and see the particles accumulated in the filter. Air purifiers will remove dust and other particles from the air, but will not remove dust or dirt from surfaces. Fortunately, whether your suffering is due to pollen in the air or your boyfriend's cat sitting on your lap, an air purifier can provide you with some relief.