The heater was too small to heat up my home sauna. I have a nicely built, nicely insulated home sauna that is a little to big for the small heater. My return window closed before I ever tried it out and was disappointed that it was too small. I ordered the 9 KW heater, and boy that one is overkill, but I only have it on 25 minutes and turn it off, and have a nice hot steamy sauna at 130 degrees. The small heater works, just make sure your space is small enough for it.