The Tuff Resistance Vacuum Hot Water Unit utilizes high-end electric heating elements to ensure the safe and reliable operation of the unit. The electric heating elements directly heat the heat transfer medium (water), and the upper heat exchanger achieves a high heat transfer coefficient with a heat exchange efficiency of up to 99.99% when exchanging heat between vacuum steam and cold water. Since the temperature of the heat transfer medium is controlled below 100°C and the exterior of the equipment is insulated with high-strength thermal insulation materials, the external surface temperature remains low, and heat loss is less than 1%. As a result, the overall thermal efficiency of the unit can reach more than 99%.