HUUM DROP 9DROP Series 9kW Sauna Heater The design of the award winning HUUM DROP 9 electric sauna heater was inspired by the purest element in nature a drop of water. This compact 9kW wall mounted electric sauna heater is engineered for sauna rooms up to 530 cubic feet (CF). Its large rock capacity ensures a consistent, soft high heat. The design of the HUUM DROP sauna heater is inspired by the purest element in nature a drop of water. Its rounded design