Summary: I've hated how quickly dust accmulated on surfaces in my home. After a bad case of allergy, I decided to buy a air purifier. My main concern was the noise generated by air purifiers. After an extensive research on the Internet, I decided to go with the Sharp KC850U, and it didn't disappoint. It is super quite--I leave it in the bedroom and I can barely hear it except the occational "gulp" it makes when it draws water from the water tank.
Summary: While traveling in Japan I came across one of these in my hotel room. The control panel was in Japanese so I found the English manual online and gave it a try. The first night I was amazed at the air quality in the room. Best description - like fresh, clean air in a forest. I immediately bought one for my master when I returned home. I use it about 75% of the year and sleep much better with it. I'm looking to buy another one now for my son who has allergies.
Summary: Their plasma claster technology is amazing! When I once bought their small air purifier for my girlfriend to put close to bed, she recoverd from chronic coughing. That's why I bought one for myself. As for humidifying function, it doesn't humidify so quickly, but it doesn't make damp either. On the whole, it has humidifying and air-purifying fucntion together, and you must be relieved to get this stuff. They have been a top brand in Japan in this sectoer.