Allergies occur when a person’s immune system overreacts to normally-harmless substances called allergens. Allergens may come into contact with the body in many ways, including airborne particulates, food ingredients, or insect stings. Some of the most common types of allergies are to airborne particulates, such as pollen, dust, mold, and pet dander (usually in the form of shed hair or skin particles.) These allergies can be alleviated in various ways, but one of the most convenient is through the use of an air purifier for the home. These units can be purchased new or used for reasonable prices and at excellent quality. The most effective way to alleviate indoor allergens is to eliminate the source of the allergens—for example, by improving ventilation systems or by weatherizing windows and doors. However, investing in one or more air purification units is a good idea even in well-constructed homes.

Air purifiers come in a range of shapes and sizes, from small standalone units to larger units that work with the ventilation system in the home. Air purifiers also use a variety of methods to purify air, the most common and basic of which is the use of a simple air filter which screens out particulate matter too large to pass through the holes in the filter. However, this technique may still allow very small particles to pass through unimpeded, and many allergens—including some organisms—are tiny. More sophisticated purification methods use ultraviolet light to sterilize the air, removing bacteria and other harmful or allergenic microorganisms. Still another purification method is that of ionization, using electrical charges to produce ions, which then adhere to airborne particulates. The ions are then electrostatically attracted to a collector, and disposed of. Possible drawbacks of air purifiers include noise and rare byproducts, most notably small amounts of ozone from certain types of ionizing purifiers. Ozone itself can be an allergen.

While there are many possible methods of air purification, do not assume that only one may be used at a time. Using several different types of air purifiers will give you the best chance of screening out allergenic substances.