摘要:Taking a barber shop in Dezhou City of Shandong Province as an example, this paper calculates the required heat by using 300 liters of 40 °C hot water every day, introduces the working principle and system characteristics of electric water heater and solar water heater, selects the mainstream products in the market, and calculates the use cost. The comparison shows that the price of electric water heater is low, but the annual cost is high; the price of solar water heater is high, but the annual cost is low.