Narvi Ultra Big -sauna heaters are efficient in heating up bigger saunas, which are heated daily. Due to the large stone compartment, the Ultra Big-sauna heater gives excellent steam for the sauna goers. The sauna heater parts are made of quality steel to stand heavy usage and corrosion. The effect of Narvi Ultra Bifg is 18-33kW.

The functions of the sauna heater are controlled by a separate control panel and power unit (bought separately). The heater  requires an external temperature sensor (included in the separately bought control unit), which makes sure that the desired temperature remains accurate in the sauna.

The diameter of a heating element of electrical heaters made by NARVI Oy is exceptionally big (8.5 mm). This extends the usage life of a heating element and significantly reduces the risk of overheating.