Review on Envion TPP220 Air Purifier Tower with Handle and HEPA-Type Filter Technology (White) by Tim Arnold

We already had one of these air purifiers, so I knew it when we bought it. I use it at night while sleeping. Some people might not like the background noise, but that was one of the reasons I bought it. I like rhythmic, humming background noise when I sleep. There are low, medium and high settings so they can be easily controlled. Very satisfied and so it has a hepa filter that does not need to be changed that we can clean ourselves.