A road covered with multilayered snow/ice (s/i) model called multilayer model was proposed in this paper and applied to the melting process of s/i layer on a pavement block in a low temperature room.Consequently, it was found that (1) the multilayer model could reproduce reduction of the thickness of the s/i layer, the volumetric ice content and temperature better than our previous model, i.e., the single layer model, (2) an accurate analysis of the melting process of the s/i layer requires that the element size (thickness) should be chosen less than 0.2 of the initial layer thickness, (3) the energy balance is effective in understanding the melting process of the s/i layer.

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We must develop many techniques for the usage of a natural energy from the viewpoint of energy saving and keeping environment clean. In this study, we developed a simple system that could control both temperature and humidity of a general office, when we could use snow stored until summer as a cold heat source of an air-conditioner. In this report, we adopted a most simple analytical model of all air, central control and variable air volume type air-conditioner which had a blower and a single duct in order to investigate the basic characteristics, and we examined temperature and humidity analytically. As a result, the temperature of the air conditioner area could be achieved 17°C of air at the entrance and 27°C at the exit which temperatures were purposed in this analysis. However, the mean humidity of 60% could not be achieved under lower fresh air humidity than 55%, and the mean humidity became the near to the humidity of fresh air. Because this snow air-conditioning system has excellent controllable characteristics and succeeds a filter effect at the snow surface, we can hold expectation to spread this system in a snowy district widely.

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Energy, food, the environment are basics of the life. The snow can contribute to these many problems to have greatly even if not decisive. The snow/ice as the cold heat source has a remarkable substitute effect for fossil energy as energy. And there is not the discharge of the warm temperature from a system depending for a mechanical refrigerating cycle, and there is an effect for environmental safeguard without using refrigerants such as Freon with this snow air conditioner. In this study, the authors have suggested many systems of the air-conditioner in which the snow is used for cold heat source, and the authors call them all-air type snow air-conditioner and have been analyzing the performance of them. This snow air-conditioner is made by simple construction of a snow storage room, a blower and a dumper for regulation of air flow. The temperature/humidity of the conditioning area is controlled by the mixing hot return air and chilled air from the snow storage room. In this report, the authors discussed on the simplest system among many all air type snow air-conditioning ones. In this system, only the temperature in the air-conditioning area is controlled and this temperature is adjusted by mixing with the circulation hot air through a dumper and the cold air cooled by the snow, and the authors call this system all-air type temperature control β system. In this paper, the system is classified into different three models for the analysis, and characteristics of them are investigated analytically and discussed.

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