The temperature in Hami is very low in winter, so the coal-fired boiler in my hotel will be demolished. What kind of water heater is suitable for hot water engineering in a hotel in Hami area?

Hami area is very special. The lowest temperature in winter is -30 degrees, and the average temperature is-10 degrees. In fact, local coal is very cheap and coal-fired boilers are better. However, considering the policy and environmental protection, coal-fired boilers must be dismantled. Let's use an engineering electromagnetic energy water heater. This machine has a thermal efficiency of 10, which is very energy-saving and cheaper than coal-fired boilers. A ton of hot water is about 3-6 degrees.