You've been probably keeping the windows closed and staying indoors more often than not during these cold winter months, and that means interior air quality can take a big dip. Asthma and allergy sufferers are particularly sensitive to changes in air quality, and adding a HEPA air purifier can make a huge difference between comfort and discomfort. I've owned a RabbitAir for a few years now, and it's proven to be one of the quietest models, capable of handling up to 700 square feet, and sips just 7 watts at it's lowest setting. What I like best besides the improved air quality while the unit is on is the addition of an air quality sensor indicator light: when it turns from blue to magenta, I know it's time to turn up the unit to a higher setting. Also, a wall mount installation and the flat modern form factor makes the MinusA2 one of the least decor-intruding units out in the market.