| 摘要 |
PROBLEM TO BE SOLVED: To provide a water heater having improved efficiency of heating.SOLUTION: A water heater includes a hot water storage tank 1, a heating means 6 for heating water in the hot water storage tank 1, and a heat exchanger 9 arranged in the hot water storage tank 1, having a flow path 9a, and raising a temperature of hot and cold water flowing in the flow path 9a by heat exchange between hot water in the hot water storage tank 1 and hot and cold water flowing in the flow path 9a. The heat exchanger 9 has a spiral-shaped part where the flow path 9a is wound in a spiral-shape, the spiral-shaped part has a substantially cone-shape such that the flow path 9a on an inner side is located higher than the flow path 9a on the outer side in the vertical direction, hot and cold water flowing in the flow path 9a flows in the spiral-shaped part from the inside to the outside, and thus agitation action in the hot water storage tank 1 due to a descending water flow produced around the flow path 9a is suppressed, reduction of an available hot water amount caused by expansion of a mixing layer is prevented, and favorable ease of use and high energy saving performance can be achieved. |
