摘要 |
PURPOSE:To make the heat transmission efficiency of fins high and to make the time period long during which gaps between fins are filled with frost by alternately superposing first fins in which raised parts are arranged in a checkerboard pattern and second fins in which raised parts are also arranged in a checkerboard pattern but do not overlap the first fins. CONSTITUTION:Multiple first raised parts 7a, 7b, 7c, 7d, 7e are arranged in a checkerboard pattern on the surface of a first fin 6a facing in the direction of stage of a heat transmission pipe 2, and the second fin 6b has a checkerboard pattern of raised parts 9a, 9b, 9c, 9d which do not overlap the raised parts 7a, 7b, 7c, 7d of the first fin 6a in the direction of superposing the fins. By alternately superposing those two kinds of the first and second fins 6a, 6b which have different fin configurations in the direction of superposing fins, a heat exchanger having fins is made up. By this constitution, the heat transmission efficiency can be made high, and the time period long during which gaps between fins are filled by the thickness of frost that grows between the fins so as to lengthen the sustained operation under a heating mode with a reduced number of defrosting operations. |