Some air purifiers with high ratings include the RabbitAir MinusA2, Coway AP-1512HH, and Alen BreatheSmart, according to LiveScience.com. All of the air purifiers are relatively quiet, with the noisiest being the equivalent of a box fan.
The RabbitAir MinusA2 is an air purifier that is sleek and attractive, and it can filter the air up to four times in a 350-square-foot room. The Coway AP-1512HH has four filters, has Energy Star certification and covers a space of about 236 square feet. The Alen BreatheSmart also is Energy Star-certified, it can filter up to 1,100 square feet of space, and it has an indicator that alerts the user when the filter is dirty.