KIP Series 4.5kW Sauna Heater Package, Built-In Controls, Stainless Steel The Harvia KIP 4.5kW Sauna Heater Package with Built-In Controls comes complete with the KIP45B Sauna Heater and Sauna Stones. This traditional stainless steel heater has a dual wall construction that allows the exterior to remain cool to the touch and heats up fast in sauna rooms from 100 to 210 cubic feet (CF).