The optimum specific sense temperature is estimated from the result of areal heat load, natural room temperature, and evaporation rate of the perspirable building. For example, Figs.9 and 10 show the relationship between natural room temperature (average in summer) of un-air-conditioned room (B/K and E/U) in Tokyo and the total evaporation rate (in summer) for each specific sense temperature. Furthermore, Figs.11-14 show the relationship between heat load (sensible heat) in summer and the total rate of evaporation (in summer) for various areas and for each specific sense temperature. The result of Tokyo in Figs. 9 and 10 shows that the average natural room temperature decreases and the amount of evaporation become bigger as the sense temperature lowers. Similar tendencies are seen in various areas. From Fig.12, as for the decrease rate of the heat load to the change in the sense

Fig.9 Relationship between average natural room temperature Fig.10 Relationship between average natural room temperature and total evaporation rate in room B/K in Tokyo and total evaporation rate in room E/U in Tokyo

Fig.11 Relationship between specific sense-temperature, Fig.12 Relationship between specific sense-temperature,

seasonal total sensible heat load and evaporation rate in Sapporo seasonal total sensible heat load and evaporation rate in Tokyo

Naha (May-Oct.)
100
80 $ A. 60 40 о Рч > 20
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80
60
0
Fig.14 Relationship between specific sense-temperature, seasonal total sensible heat load and evaporation rate in Naha
Fig.13 Relationship between specific sense-temperature, seasonal total sensible heat load and evaporation rate in Osaka

temperature (in Tokyo), the inclination is the largest between 30 °C and 25 °С, though the increase inclination of the amount of evaporation becomes also large. 25 °C is considered as one standard of the set specific sense temperature in Tokyo. At the specific sense temperature of 25 °C in Tokyo, the average nature room temperature of LD room decrease by 0.9 °С and the energy-saving rate becomes 28% by autonomous perspiration, as compared to the non-perspiration case in summer. As the optimum specific sense temperatures, 25 °С in Sapporo and Osaka, and 30 °С in Naha can be proposed from the simulation result of Sapporo, Osaka, and Naha, the same way. In this case, the energy-saving rate becomes 65%(Sapporo), 29%(Osaka) at the sense temperature of 25 °С and 18%(Naha) at 30 °С respectively. Moreover, at each optimum specific sense temperature, the average nature room temperature of LD room in summer lowers by about 0.6 °С in Sapporo, 1.0 °С in Osaka, and 0.8 °С in Naha respectively, as compared to those of non-perspiration.

5. Conclusion

As one of the functions of heat dissipation of human bodies, the author took up the perspiration function and applied it biomimetically to passive cooling in buildings. A perspirable building, the walls and roofs of which can perspire with the use of thermo-sensitive hydrogel was developed. The improved perspirable roof to strengthen nonflammability was examined. The details of the perspirable building and the passive cooling effects and energy saving effects by means of evaporative cooling were examined. The experimental and theoretically simulated results of the perspirable building showed that passive cooling effects and energy saving effects by evaporation were great, as compared to those of the building unable to perspire. Further the areal optimum specific sense-temperatures of the perspirable roof with thermo-sensitive hydrogel were predicted by analyzing the simulation results of room temperature and thermal load in a typical Japanese detached house perspirable.

Acknowledgement

The author acknowledges Dr. Ikusei Misaka, Takenaka Corporation, Mr. Hiroshi Oka and Mr. Takeshi Maruyama, Kohjin ^.,Ltd., Mr. Tetsuji Oshibe and Mr. Fumio Tani, Nitto Boseki ^.,Ltd. and, Dr. Hiroaki Kitano, Mr. Takeshi Iwata, Miss Miyuki Moriyasu and Mr. Taichiro Nagatani, Mie University, for their kind cooperation in the execution of the study.

References

[1] Y. Ishikawa et al., Development of a Solar Control Window Utilizing the Seasonal ^ange in Solar Altitude, Journal of Technology and Design, Architectural Institute of Japan, No.6, 1998

[2] Y. Ishikawa et al., Development of a Solar ^nlrol Window with Rotating Blind of Different Thermal Characteristic Slats, Journal of Technology and Design, Architectural Institute of Japan, No.10, 2000

[3] Y. Ishikawa, Passive doling Effect of Water Evaporation in Perspirable Building, EuroSun2006, 2006

[4] Y. Ishikawa, A Study on Simplified Room Temperature Calculation of Multi-room Building Roof Sprayed and Thermal Effect of Roof Spraying (Part. 1), Transactions of Heating, Air-conditioning and Sanitary Engineers of Japan, No.30, 1986

[5] Y. Ishikawa, A Study on Simplified Room Temperature Calculation of Multi-room Building Roof Sprayed and Thermal Effect of Roof Spraying (Part.2), Transactions of Heating, Air-conditioning and Sanitary Engineers of Japan, No.30, 1986