In the past I had used a humidifier that heated the water and produced a steam mist in order to raise the humidity. There was a wait time to get steam since it had to heat the water first. With this puregardian humidifier, ultrasonic technology is used to produce the water vapor. This means that you have instant water vapor. As soon as I turned the unit on, it immediately began producing mist.
There are three settings: low, medium, and high. You just push the power button once to turn the unit on and get low mist. Push it again to get medium. Push it again to get high. Unfortunately there is no indication as to what setting you are on, though you can tell by the amount of mist being generated. The tank is coated with something called Silver Clean Protection which is designed to inhibit mold and mildew buildup. With my heated humidifier, I had to treat the water container with a bleach/water solution every week or two, or otherwise I got a weird odor from the unit. They claim a 30 hour run time using the low setting. I always take these ratings with a grain of salt. A nice touch is the night light, which illuminates the unit with a blue glow – that looks cool. It runs very quite. This unit is designed for small rooms.
For my test of the unit, I put it in a room about 12 x 10 feet. I placed my temp/humidity gauge on the other side of the room from the dehumidifier. I had the measuring gauge placed about four feet high. My starting humidity was 45%. After about one hour of run time on the low setting, the humidity rose about 6%. I then ran the unit on high for another 30 minutes. The humidity rose 7% in that half hour. When I finished the testing, the humidity in the room was at 58%. Normally I would not use a humidifier at this humidity level, but I did so because I wanted to test the device's performance. If your humidity is fairly low (less than 20%), I would recommend running it on the medium or high setting. The down side to the cool mist produced by this unit, as opposed to a unit that heated the water, is that the mist tends to drop towards the floor; however, the unit does manage to propel the mist, on high, about 18 to 20 inches into the air. This would recommend placing the unit somewhere high off the floor.
So then, the unit managed to produce a significant increase in humidity in a reasonable amount of time for the size of the room, and it was very quiet. It has an esthetic appeal as well. I'm satisfied.