Well of course this Ivation 5 In One Air Purifier is quiet on the low fan setting but not so on the higher fan settings which is to be expected but it is not annoying loud the sound is quiet enough to have a peaceful sleep. I have only been running the unit for about a week so far and the print in the instruction booklet could be a little larger as even with reading glasses I have found it difficult to read. There are four purifying levels based on the size of the rooms but no mention of how long to leave the machine running while while in Ozone mode. The remote control for the unit has an eight foot limit with new batteries and it would have been nice if the remote had a further range.
Very good design, use the ozone sparsely every day for air quality maintenance. Follow instructions to setup the automatic operation. Well made, and parts are available for replacement.