I bought this product based on the description on the web site which states that it runs for 22 hours on low and covers 1200 square feet. What I found was that the longest setting on the machine is for 6 hours! A far cry from the 22 hours as promised. I have to be home to continuously push the button to get another 6 hours. What it should read is that the capacity for water is 22 hours. Very misleading communication.