Ideal for heating large areas quickly and efficiently the devil 4000 is a propane gas powered heating unit manufactured specifically for spaces such as large workshops warehouses industrial units and more producing a minimum heat output of 250 000 btu 70kw and a maximum heat output of 400 000 btu 131kw the devil 4000 can be adjusted to suit the requirements of the area it39s heating and those around it featuring fuel safety cut out feature and approved to british and european standa