We have this in our daughter's bedroom, a standard sized bedroom. It does a great job cleaning the air and keeping it clean. It's a medium size device, not so large that you'll have to set it on the floor but big enough to take up a good chuck of space on a shelf or table or nightstand. We leave it on "auto" mode so it adjusts as needed on its own. It's not silent, the fan makes a little noise, especially on the highest fan setting, but it's easy to block out and ignore. It doesn't keep her up at night or interrupt her reading or studying. The filters only need to be changed every 6 months or so. It keeps the air feeling and smelling crisp and clean, which helps to reduce her seasonal allergy issues, so we're very happy with it.