After intensive research and reading numerous positive reviews, we decided to purchase this expensive heater.  We have a trailer in which we camp in the winter, for heat we use two electric heaters one of which gave up the ghost.  So we ended up buying this one, and it does not put out any heat in a cold environment.  It was minus 6 degrees Celsius in our trailer, our ceramic heater worked just fine, and this one almost did not produce any heat at all.  After our trailer was warmed up, the heater works ok. I am sorry, but the reason we bought this heater was to heat up our trailer, therefore it missed the mark.  We would not recommend to buy it.