[in Japanese]

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The symposium on man-thermal environment systems was organized and its first meeting was held in August 1977. Since then, 16 annual meetings, including a memorable international meeting in 1992, were held successfully. This paper reviews and analyses the papers submitted at these meetings and suggests further research be conducted in certain aspects of such papers.

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Adaptability of human being to hot environment was discussed from the incidence of heat casualties, the present knowledge of thermoregulation, and from the view point of evolution. The incidence of heat casualties in Japan exceeds 150 per year during hot summer days,and the number of incidence correlates with the number of days with minimum temperature higher than 25 degree C. About 40% of the incidence are found in elderly people over 65, which suggests that elderly people are more susceptible to heat stress with less reserve capacity to tolerate heat. A guide line for the prevention of heat casualty was discussed based on the regulatory mechanism of body temperature, circulation,and body fluid. Human can tolerate the cold more easily than to heat using both behavioral and physiological thermoregulation. On the other hand,it is necessary to elaborate circulatory function and body fluid to tolerate to heat load,which leads to heat casualty more easily. This fact, together with the fact that human being has evolved through ice ages impose the necessity to brake global warming.

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A history of thermal comfort studies and Environmental Design based on interaction between human and thermal environment in Japan was reviewed from the viewpoint of architec ture and built environment. In earlier period researches in this field were strong by influenced by the hygiene. After World War II original researches have been conducted in this field. In the past five years papers and projects increase year by year. However, most of the latest studies aim on practical applications and basic research has gradually decreased. More researches based on the human heat balance equation are desirable in the neer future.

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The purpose of this study was to investigate the physiological and subjective responses of the elderly during outdoor exercise in comparison with those of the young in the four seasons. The subjects were 9 elderly people (65 to 85 years) and 8 young (20 to 22 years). They played Gate Ball (GB) games in the morning in the four seasons. During the GB games, blood pressure, heart rate and skin temperatures were measured and thennal sensations were recorded. The dry and wet bulb temperatures, wind velocity and globe temperature were also recorded every 30 minutes. In the cold environments or winter season, the elderly had a tendency to have higher skin temperatures and voted "warmer" during the outdoor exercises. The elderly had higher blood pressure in winter and a significant negative relationship between systolic blood pressure and mean skin temperature was found, but not in the young. There were few differences in physiological and subjective responses between the age groups in warm conditions. These results suggested that greater physiological strains were observed among the elderly in the cold thermal conditions.

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We investigated seasonal variations of clothing, thermal sensation and thermal comfort by conducting experiments on females during all the seasons. The experiments were conducted in climate chambers. Air temperatures were 16℃, 20℃, 24℃, 28℃, 32℃ and relative humidity was 50%. Air velocity was still air (<0.15m/s), and mean radiant temperature was equal to air temperature. Subjects were 71 healthy college aged females. They did some sedentary works in casual wear which they were dressed in, and after the experiment do value was calculated. The subjects were exposed to different conditions for 60 minutes. The subjects were asked to report thermal sensation on the 9 category scale and thermal comfort on the 7 category scale. The experiments were conducted seven times from October 1986 to August 1987. The results were as follows: 1) The mean do values of the subjects were about 0.84 clo in winter and 0.4 clo in summer. 2) The air temperatures that the subjects reported to be under thermal neutral conditions were 22℃ in winter and 28℃ in summer. 3) The range of air temperatures that they reported to be comfortable conditions were from 20℃ to 28℃ in winter and from 22℃ to 30℃ in summer. Thus they felt warm (atatakai) in winter and cool (suzushii) in summer.

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We have developed a human thermal system (AVA model) for the prediction of thermal comfort. The distinguishing feature of this system is a more precise model description of heat transfer by blood flow (i.e. the introduction of arteriovenous anastomoses (AVA) of the extremities and a dual vascular network) than conventional human thermal systems. The results are the following: (1) The experimental verification with three different steady thermal conditions (22℃, 28℃ and 34℃) suggests that the AVA model can well simulate body temperature profiles. (2) The visualized results demonstrate that the model predictions such as tissue temperature and blood temperature distributions are considered physiologically plausible.

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Experimental results on the reduction in thermal resistance under increased air velocity on a standard summer clothing ensemble as well as the same ensemble plus a sweater or a wind breaker are described. A seated thermal manikin was exposed in a climatic chamber to different air velocities. It was found that the basic thermal insulation of the summer ensemble was reduced 25% at air velocity of 1.0 m/s. The basic clothing insulation with a sweater was changed much more by increased air velocity than that with a wind breaker. The equivalent temperature taking into account the reduction of clothing insulation was derived based on heat loss from a manikin.

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Concept of pleasantness or comfort as a criterion for environmental evaluation was dicussed. Criteria used for environmental evaluation are not only various but also consist a hierarchical structure. The passive model of the human being in the laboratory study and the active model of the human being in the field survey were compared. The pursuit of positive pleasantness is valid only in the latter, and in the former it has some kind of danger. The concept of ethics in the study of pleasant environment has been set forth, because this kind of study might violate the dignity of the human being. It is, in a word, ethics for environmental control, like bio-ethics or environmental ethics.

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Four measurements conducted in conventional houses in rural area showed the present status of indoor air qualities in present Japanese houses with occupants. Measured items were carbon monoxide and dioxide, ventilation rate, humidity and temperatures. The human responses,such as heart rate, blood pressure and skin temperatures were also measured. The most remarkable results were fairly high concentrations of carbon monoxide and dioxide caused by the use of unvented combustion appliances, such as kerosene space heaters and "Sumibi-kotatsu", or traditional Japanese box heater using burning charcoals. The obvious health effects on the occupants were however not seen in the measurements. But the aged occupants were living in considerabily severe indoor environmental conditions although they are deemed to live in excellent indoor conditions since outdoor air quality in rural ares is generally good.

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A passive sampler and a measurement system were developed for the measurement of average indoor carbon dioxide concentration to evaluate indoor air quality. A plastic bottle of 140 ml had an alkaline absorption filter paper on the bottom and a cap with both a diffusion tube and a spout for gas exchange. After sampling, the concentration of carbon dioxide transported to gas phase by acidification with sulfuric acid, was measured by an infrared meter. Average concentrations were calculated with a constant on diffusion of the sampler and the gas phase concentrations. The proposed method was applied to the measurement and evaluation in residential houses and offices.

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A portable electronic WBGT-meter for estimating hot environment has been developed. The comparisons between the values of the WBGT-meter and measured values by using the standard method in the field test show good agreement. This portable and simple to operate instrument consists of two thermistor probes to measure each air temperature and globe temperature and a humidity sensor to instantly compute the WBGT indoor and outdoor indices. The meter weighs 650g. The memory is capable to store up to 999 data together with date and time, which can be transferred to a computer and a printer by RS-232C interface.

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Due to the improvement in the thermal resistance of houses the effects on heating are as follows: (1) Cancellation of temperature distribution of indoor vertical direction. (2) Saving energy effect. (3) Surface temperature of wall rises and long wave radiation becomes less. (4) Decrease of dew condensation. Improvement of thermal resistance is effective for indoor thermal environment. Thermal resistance of a window is extremely small than that of a outside wall. Accordingly the reinforcement of thermal resistance of window is important for the improvement of indoor thermal environment. A study was conducted regarding this matter. The existence of dew condensation at window surfaces and the thermal resistance of windows were examined. An experiment was carried out on a window of 213. The result is divided into 3 parts (a kind of glass, a kind of material, an opening and shutting formula of window). When a part was installed at a window, the ratio of improvement on thermal resistance and the existence of dew condensation was examined. A part of 4 kinds (a inner window, a curtain, an acrylic board, a shoji) was divided and arranged. The thermal resistance of an opening department on a building was improved by installing a part in a window. There were two effects (saving energy, improvement on residence environment). When the part which has good airtightness was installed at a window, dew condensation became few. When a part is used in the night and not in the daytime, a window does not freeze up all day.

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Monitoring method for indoor air quality control was experimentally studied for comfortable offices and residential houses. The experimental room has an invertor-control fan and a filter unit. For air quality control, dampers of outdoor air introduction, filtering and air cleaners, an electric dust collector and an ozone deodorizer, were handled. In this experiment the room air was ventilated with outdoor air through the filter unit. After the fan stopped, contaminations were generated from occupants and/or smoking, and these control units were handled. The generation rate and removal efficiency were evaluated by monitoring of the contaminants in air of the experimental room. The results show that carbon dioxide, carbon monoxide and methane were removed only by introduction of outdoor air and suspended particles by both filtering and the dust collector, and a part of non-methane hydrocarbon, VOC, was removed by the deodorizer. The semiconductor gas sensors detecting contamination level by smoking responded to handling of outdoor air introduction, the deodorizer and filtering by active carbon. Therefore, it is considered that monitoring with the semiconductor gas sensors is effective for air quality control. The relationship between outputs of these monitors and vote values of air quality by panellers was investigated.

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