| Summary |
With the aim of embodying its educational policy whereby emphasis is placed on a favorable relationship with nature. Hiroshima Gakuin High School has adopted a tension membrane-structured roof for its Xavier gymnasium, to create a bright space integrated with the campus which is surrounded with greenery. This roof is framed with places of glue-laminated lumber, over which a 0.8mm thick single-layered membrane composed of glass fiber base sheet coated with teflon is laid. While the membrane-structured roof has the major advantage of being translucent, it also admits the penetration of solar radiation, so sufficient study of the indoor thermal environment in the summer period would be required. Since this facility is a gymnasium for the junior and senior high school students, the plan excluded the use of active cooling, but aimed at planning and implementing the proposed roof spraying system as a means of passive cooling utilizing natural energy. The principles are that water is sprayed onto the membrane roof surface to reduce its temperature through the cooling effect of evaporation into the open air, thereby facilitating the passive cooling of the gymnasium inner space. This paper begins with outlining the roof spraying system by means of evaporative cooling, and discussions on the results of the field measurement of its thermal effect, which is carried out on typical summer days. Through fie1d measurement, the author has proved that roof spraying reduces the indoor PMV and SET*.
which further leads to a decrease in PPD. Roof spraying enhances the indoor thermal environment and produces a noticeable passive cooling effect. Furthermore, this study has provided field measurement data representing the lighting characteristics of the single-layered, membrane structured gymnasium.
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