Two entrepreneurs have figured out how to heat their homes for free: bitcoin mining. Bitcoin transactions require a lot of processing power, which creates a lot of heat. So Ilya Frolov and Dmitry Tolmachyov built a wooden cottage in the Russian Siberian town of Irkutsk, and they’re heating it with two bitcoin mines. The men pocket about $430 a month from bitcoin transactions, while keeping the 20 square meter space warm. Watch our video to see how the heating system works.