I was looking for some sort of heat source to keep my 9’x12’ greenhouse heated to 23 degree CI stumbled across these units. Unbelievable! This unit is self contained, super efficient, portable, super reliable, and the thermostat is adjustable from 8C to 30 Plus C. It is super easy to operate. It takes a minute or so preheat the glow plug and system but that’s how they work. Within a minute you have warm/hot air blowing from the flexible output hose. You simply press the Power button and the toggle through the display to the Temp page and simply select the desired temperature by press the Up or Down buttons.I have used it now for 3 weeks in temperatures down to minus 2C. I had the unit set for 11C.It burned 1.5. - 2 liters of fuel in a 12 hour period overnight. Excellent! Also the fan output increases at start up and then nicely slows down as the unit reaches the desired temp. This gives excellent air flow. When fan is on high it is very powerful. This is not a toy. It works,perfectly!I like this unit so much, I ordered and now have a second unit to keep at my lake home to preheat my riding snowblower’s engine.