The wooden dutchtub is a wood fired eco friendly outdoor hot tub with ingenious simplicity the water in the tub is heated by the naturally occurring thermo syphon effect through the coil a fire in the centre of the coil warms the water inside the coil the warm water expands and flows out the top of the coil while drawing in cool water from the bottom of the tub the dutchtub wood weighs only 85kgs when empty this makes the hot tub lightweight and portable the dutchtub wood fits 4 people