The collection sheet is not noticeably getting dirty?
There can be a number of factors that can attribute to the lack of contaminants on the collection sheet. First, keep in mind, most contaminants are in micron size and are not noticeable by the naked eye. It is a matter of accumulation of contaminants before one can notice them. Turn the dial all the way clock-wise, if possible, to ensure maximum efficiency. Make sure the ionization line is clean and in good condition. We recommend changing them every 2 years after normal regular conditions. We recommend leaving the SilentAir air purifier in one location, versus moving the air purifier from room to room.
