IKI 12kW makes for a great sauna experience, ample heat and pleasant moist steam to cover a large sauna room. The big brother of the IKI 6 kW heater is ready with an hour's warming time and can serve larger groups of sauna-goers with a hefty and memorable sauna experience. The fast heating time is made possible by free air flow through the heater's stainless steel mesh frame and the large contact area between the stones and the resistors. This heater can be used in private saunas but is powerful enough to be used for hotels, spas and other public saunas. The narrow stone pillar allows for larger benches in the sauna. The heater is equipped with a separate control panel.

A study carried out by the Lappeenranta University of Technology has determined that IKI heaters in commercial use preserve energy. Because the large mass of stones preserves heat effectively, electricity can be switched off periodically, while the heater continues to heat the sauna room and give out steam. This means less is used than with heaters that have a smaller stone capacity. IKI can be made to order, which means it can fit any space of any size.