In order to confirm snow melting effects and also to find out involving problems, tests were carried out by the electrically heated roof-tiless (ERT) at a model house from January 1989 to February 1990. The roof was covered with the lines of the ERTs and non-heated tiles. Each line of ERTs was heated independently. Two kinds of test for snow melting were carried out. In a complete snow melting test, as snow melting on the lines of ERTs progresses, snow on the line of non-heated tiles slides down to the line of snow-slide-stoppers. It suggests that the arrengement of ERTs near the snow-slide-stoppers is effective for a fewer ERTs usage. In a partial snow melting test, snow caves were formed over the lines of ERTs. The formation of snow caves affects little snow melting efficiency in this experiments. The amount of water collected through the eaves trough, which is another form of molten snow, was measured with a pluviometer. From the time variation of this water, melting efficiencies of four tests by using the ERTs were obtained ranging from 33 to 40%.

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