Spirit Series 9kW Sauna Heater Package, Black The Harvia Spirit 9kW Sauna Heater Package comes complete with the Spirit SP90E Sauna Heater, Xenio Wi-Fi Control, and Sauna Stones. This premium-quality heater package has an elegantly curved shape, allowing it to heat quickly to your desired temperature in sauna rooms from 177 to 494 cubic feet (CF). Please note: Must install per the instructions in the heater manual. Please note: Must install the sensor included with the heater per the instructions in the heater manual.