I recently just built a new garage and built a sauna in it. I am having issues getting the temperature above 150 degrees. I am currently using a 2220V Turku 9kw heater in a 280 cubin foot room. The walls are insulated by R30 in btw stud walls/cielings, an r15 reflective foil barrier and 6 mill vapor barrier. The the finish is a shiplap.