We’ve all done it. Wandering through the mall, something in your favorite gadget store catches your eye. Before you know it, you’ve spent a good amount of cash on a product that looks really cool, but will probably end up in the back of a closet.
In conversations with patients and friends, it seems that air purifiers are the must-have gadget of the moment. The question is, do they really work, or are they just another impulse buy destined for the garbage bin?
How Air Filters Work
As I researched studies and reports on air purifiers, I discovered that approximately 250 million dollars are spent each year on these machines. In most cases, asthma and allergy suffers are the ones making the purchases hoping that the machines will clean the air in their homes and grant them some respite from their symptoms. In order to provide my patients with the best advice, I decided to look beyond the hype and see if they really work.
When it comes to the sleek and often expensive air purifiers you see at the mall, there are generally two ways in which they attempt to purify the air. Some models are passive, allowing air to naturally circulate through the machines, which trap dust and floating debris using metal plates with an electrostatic charge. The newly cleaned air then naturally circulates back into your home.
The second type of air purifier works in a similar fashion, but uses a motorized fan, which moves the air through the machine. This method cleanses more air and also keeps are circulating through a room better than the passive models.
Dangers and How to Avoid Them
The main problem with air purifiers, especially the passive kind, is that most allergens are too heavy to be airborne. Rather, they lurk on carpets, clothes and furniture and will never enter a passive air purifier. A motorized model will encourage more circulation and keep allergens from settling in your home.
Unfortunately, most homes are not tightly controlled environments like testing labs. Therefore, other factors like roving pets, open windows, and dirt on shoes mean that overcoming the allergens in a typical home is an uphill battle, even for the best air purifier.
Another factor to examine is what happens to the allergens and dirt that the purifier collects. In some cases they stay trapped in the machine. The drawback is that the filters or metal plates must be cleaned regularly, exposing the owner to all the irritants he or she wanted to escape in the first place. Other types of purifiers emit ozone as the by-product of the cleansing process. Ozone protects the earth’s atmosphere, but it is also a toxic gas. The ozone released by your air purifier could cause health problems due to prolonged exposure in confined spaces like a bedroom or small office.
Though some of the information I uncovered is discouraging, air purifiers should not be dismissed completely. The key is to make them one part of your effort to lower allergen levels at home. Good cleaning habits go a long way and can help your air purifier do its job efficiently. Next time you’re at the mall, look for a model with a powerful motor that is either no-ozone or low-ozone producing. Also, any model worth considering should be outfitted with a HEPA or “high efficiency particulate filer.”
One brand that I like is IQ Air, which makes air purifiers that produce no ozone. Their “HealthPro Plus” is a Consumer Digest Best Buy and was named “best air purifier” by Wired magazine. Another excellent model is the Blueair ECO10, which has patented filter technology and a two-speed motor running on 95% less energy than similar machines, making it highly energy efficient. Armed with this information, you can make the best decision about using air purifiers to help control allergies.
Mark Rosenberg, MD