| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-efficiency water heater which can properly prevent or suppress such a malfunction that a primary heat exchanger is liable to be corroded due to the generation of a strongly-acidic drain. <P>SOLUTION: The water heater WH1 comprises the primary heat exchanger HE1 having heat exchange tubes T1, T2 as tubes having copper-made fins, and a secondary heat exchanger HE2 having acid-resistance heat exchange tubes T3, T4. The heat exchange tubes T1, T2 are aligned in a direction in which a plurality of linear tube bodies 11a, 11b are aligned in almost parallel with each other and which crosses a combustion gas progressing direction, ends of the tube bodies are connected to each other in a meandered shape via connecting tube bodies 12a, 12b, in the primary heat exchanger HE1, the meandered heat exchange tubes T1, T2 are arranged in a single stage in the combustion gas progressing direction, and other heat exchange tubes are not arranged upstream and downstream of the combustion gas progressing direction rather than the single-stage heat exchange tubes T1, T2. <P>COPYRIGHT: (C)2013,JPO&INPIT |
