Most physicians will confirm that an allergy air purifier is an essential part of an effective management plan for those whose condition is triggered by airborne allergens. But in order to be effective it should have the following 5 features.
Filter For Particles—Many of the irritants that trigger airborne particles are found in the air. Seasonal pollens, dust, dust mites, mold and mildew spores, and pet dander can trigger symptoms and even a flare up for those who have allergies.
HEPA or high efficiency particle arresting filters can successfully eliminate airborne particulates that are as small as .3 microns in size. This includes all of the triggers listed above. However, many of these solids can be eliminated by filters with bigger openings and that are far less expensive.
Pre-filters are made of a cotton ball sort of material and can trap the bigger particles in the air that can be seen with the naked eye. Having these filters as part of the filtration system can prolong the life of the HEPA which will save you time and money down the road.
Filter For Gases—Gaseous pollutants can also cause problems. Things like smoke, fumes from household personal and cleaning products, chemicals that off-gas from carpet, pressed wood furniture, and paint can all cause flare ups.
Carbon cloth in a purifier is invaluable. Originally designed by the British Military as a response to chemical warfare, this type of filter offers dual benefits. Because it is made of carbon it can effectively eliminate gases, odors, and chemicals. And because it is woven like cloth, it gives additional protection against particles.
Canister of Filters—The more filters present in a unit, the more filtration you receive. This seems like a no-brainer, but there are cleaners with no filter or just one filter. It seems reasonable to assume that a purifier with a canister of filters will last longer and require less maintenance than one with one filter or no filter.