In recent years, The double skin (DS), which is aimed at reducing the environmental load, has been used in the façade of various buildings. In particular, the ventilation performance of the DS is the most important factor in reducing the cooling load. Therefore, in this study, we analyzed the ventilation volume of natural ventilation from experiments using forced ventilation with an air supply fan and carbon dioxide concentration method in an actual building that adopted DS and clarified the thermal behavior of DS. In forced ventilation, the ventilation air volume is large, and the amount of heat removed is large even if the difference between the DS temperature and the outside air temperature is small. The total effective area αA was obtained from the natural ventilation experiment, and the theoretical values for both forced ventilation and natural ventilation followed the measured values. Simulations showed that the cooling load on the reference floor of the office building decreases by approximately 10% when DS is installed. The effect of different ventilation rates was examined, and it was found that increasing the ventilation frequency reduces the cooling load, but when it exceeds 30 times / h, the change in the cooling load is small. When the ventilation rate in the DS was 30 times / h, each perimeter of the annual cooling load was decreased by approximately 21 to 23% for the south and west perimeters and by 8.3% for the north perimeter.

The objective of this research is to quantitatively demonstrate the feasibility of demand response (DR) for an existing district heating and cooling (DHC) system with thermal storage tanks using a detailed simulation. It should be noted that the DR framework and costs considered in the feasibility study were based on the emerging Japanese DR market. We first assessed the situation of the DR market in Japan and clarified the DR directives to be covered and the cost conditions to be assumed. Then, we presented a strategy for utilizing thermal storage tanks in DR for peak reduction and conducted simulations of the DR in summer and winter using the proposed strategy. Based on the assumed DR market and the simulation results, the economics of the DR were evaluated. In addition, we evaluated the interim period to study DR for demand generation, which is currently under institutional design and is considered necessary in the near future. With regard to DR for peak reduction, it is necessary to operate the DHC system in preparation for full storage at the start of the DR, and in summer, it was shown that the DR-kW increases from 591 kW to 825 kW by storing heat for hours until the DR starts. From an economic perspective, it was confirmed that suppressing the increase in the maximum demand from 972 kW to 44 kW by imposing restrictions on the number of operating heat source machines, resulted in a cost benefit. It should be noted that it is difficult to deal with a prolonged period of time, such as the supply-demand crunch that occurred in March 2022, owing to the capacity of the thermal storage tanks. With regard to DR during the interim period, it is anticipated that DR will be issued on consecutive days. It was also confirmed that the amount of heat available for DR during the interim period depends on the amount of heat used on that day, since the air conditioning load is low. Therefore, the simulation results show that it is feasible to implement DR in the interim period, although the volume is not very large, and with an average DR-kWh of 4,091 kWh/day, the average cost advantage is 28,580 yen/day. The DR market in Japan is in the starting stage, and the system and unit prices have been fluctuating greatly. Therefore, it is necessary to consider operation methods in accordance with the changes in the system. As shown in this research, it is possible to consider control methods for DHC systems in accordance with the system and unit prices by using simulations.

In rooms with large windows, the thermal environment tends to deteriorate owing to thermal radiation, cold draft, and vertical temperature difference during air-conditioned heating in winter. To improve the thermal environment near windows with low insulation performance, equipment such as perimeter fans and natural convection type heaters are used. In this study, a calculation model of the plume formed near the window surface due to perimeter heaters installed under the window is constructed to apply the vertical temperature distribution prediction model. The effectiveness of the calculation model is demonstrated by comparing it with the results of experiments conducted to understand the effect of cooled window on the upflow.

In recent years, there has been significant attention on not only the improvements in residence conditions but also the promotion of health by improving the social environment including the working and regional environment. Because of the significant amount of time that office workers spend in the workplace, proper modification of their working environment and work habits could potentially improve both their intellectual productivity and physical health. Therefore, in 2018, we developed CASBEE-OHC, a subjective assessment tool for the working environment with a view to improving workers' intellectual productivity and health, and conducted a WEB questionnaire survey. The results of the questionnaire survey using CASBEE-OHC suggested that the surrounding environment may affect worker health and productivity. However, the relationship between workers and offices has now changed with the spread of the new coronavirus epidemic and other changes in the relationship between workers and offices, such as the widespread implementation remote working. Therefore, this study will identify the changes that have occurred in the relationship between workers' surroundings and their health since the previous survey. For workers whose subjective work efficiency and health scores have improved or declined since the previous survey, we will focus on items that are associated with the changes in scores and examine factors that have led to improvements in worker health and productivity. The first method of analysis was a simple tabulation and regression analysis of the current worker's surroundings. Next, logistic regression analysis was performed on changes in health status and work efficiency to analyze the factors influencing the improvement in scores. The results were as follows: 1) From the simple tabulation, CASBEE-OHC, WFun, and subjective work efficiency scores were ascertained and compared with the previous survey, revealing an increase in each score. 2) The regression analysis showed that the influence of the surrounding environment on subjective work efficiency was similar to that observed in the previous survey, suggesting that the influence of the office environment was significant. Regarding the influence of the surrounding environment on occupational dysfunction, the results suggest that the influence of the home environment is significant for mild occupational dysfunction as in the previous survey, while the influence of both the office environment and home environment is significant for severe occupational dysfunction. 3) Regarding changes in the subjective work efficiency and work function impairment, the results suggest that changes in the office environment may have influenced changes in the subjective work efficiency, while changes in the office environment and housing environment may have influenced changes in WFun.