I’m a very technical person, so I made a serious evaluation. The unit is nicely made and well thought out. The day I got it, the humidity was listed by the weather bureau as being 16% - reasonably low.
I filled the tank and noted that water was running down the filter surface in the back in rivulets about 1/2 inch apart, thus it seemed to be working properly. I have two thermometers one on the wall, and another that I could place in front of the unit. I ran this "Air Cooler" for about 6 hours. I was never able to detect any drop in the temperature coming out, VS. the air in the room. I had the same experience the next day. I couldn’t believe this! With water running over the filter in the machine, and still no change in the temperature coming out.
What more can I do or say? It does not cool the air as advertised that it is suppose to! I don’t understand why not, but it just doesn’t. There are numerous businesses around here that use "swamp coolers’ which are roof mounted on their buildings, and they seem to do a fine job. thus unit would make a very nice 3-speed fan, but not for. I have a simple box fan that blows the air just as well, and costs less to run. I’m really sorry, and hope that I can return it.