After much research, I chose this air purifier, specifically. I wish I would have spent more time researching the cost of the replacement filters because I probably would have bought something else. I don't really much care for all of the bright lights on it, but it is being used in the family room...so, it's only slightly annoying. These appliances are never silent, and this one makes about as much noise as I expected, no more than the old unit that it replaced. I'm not sure how to tell if it works as described, but the lights are one and it's humming away.