"The bottom line: Ionic air purifiers have undeniable appeal, but there’s a problem: They don’t really improve air quality, says Dr. James Sublett, a clinical professor at the University of Louisville; a fellow at the American College of Allergy, Asthma & Immunology; and co-chair of the 2007 ACAAI Healthy Indoor Environment conference. “We [allergists and immunologists] generally don’t recommend them,” he says. “This is a windmill that I’ve been tilting at for a number of years.”
According to Sublett, the devices don’t effectively remove dust, dander and other irritants from a room. Without fans, he explains, they can’t collect airborne particles from more than a few feet away. And when even small amounts of dust enter the device, the plates inside quickly lose much of their power to attract more particles. Meanwhile, the charged particles that stick to walls or TV screens haven’t left the room and can always billow up again to cause trouble."