Kazuaki Nakaohkubo’s research while affiliated with Saga University and other places

This study aims to develop a thermal environment simulation tool to support urban planning, utilizing PLATEAU, a 3D urban model maintained by the Ministry of Land, Infrastructure, Transport and Tourism. The tool is configured to be operated using two components. The first component is used to add information on trees, buildings, and land use to the PLATEAU data. The second component is used to create voxel for calculations, calculate heat balance, and output visualization files. This tool allows the evaluation of thermal environment in wide urban areas, take into account the effects of urban greening and urban redevelopment.

The thermal design of buildings in hot summer and cold winter regions must meet the requirements of thermal insulation in summer and heat preservation in winter. As a vital component of national compulsory education, primary schools must create a good indoor thermal environment for classrooms, which is particularly important for students. Due to the lack of construction standards and limited research on Chinese regions with hot summers and cold winters, policymakers have no comprehensive and efficient approach to creating optimal indoor thermal conditions in primary school classrooms. Therefore, based on the climate conditions of hot summer and cold winter areas, this study conducted field surveys in primary and secondary schools in hot summer and cold winter areas, summarized and analyzed the current situation of the surveyed classrooms and users' subjective evaluation of the indoor thermal environment of classrooms, and summarized the current hot summer and cold winter conditions. Problems in classrooms in primary and secondary schools in the region are clarified, and the research direction of construction strategies is clarified. The study found that most of the school hours in summer and winter were in a poor indoor thermal environment without refrigeration equipment. This study adjusted the school leaving time to 17:20 in summer and 17:00 in winter by adjusting the school leaving time to reduce the time of adverse thermal environment.

The coronavirus pandemic has led workers to remote work. This study aimed to elucidate the effect of working in green spaces in a summer nearby office in 3 experiment days and analyzed effects according to the trait anxiety tendencies, i.e., High-anxiety and Low-anxiety groups. The subjects were 27 who worked in offices nearby the experimental site (11 male and 16 female) aged from 20s to 30s. The experimental site was greened for an event in Marunouchi, Tokyo. The Visual Analog Scale results indicated that working in green spaces significantly improved workers’ subjective psychological statuses, such as “vigor,” “tension- anxiety,” and “mood,” and the questionnaire survey revealed subjective evaluations of job state, such as “enjoy” and “think deeply.” To consider effectiveness based on participants’ anxiety trends, divided participants into two groups using the score of (Y-2) in the State-Trait Anxiety Inventory. Increasing working in a green space was likely more effective for the low-anxiety group. The high-anxiety group’s subjective psychological evaluation of work status tended to improve the most by the first time working in green spaces. These observations suggested that using green spaces as a workplace provided workers process of psychological improvement that differed between the two groups.

Different functional areas within general hospitals have varying environmental requirements, with relatively high energy consumption. A comprehensive evaluation of the operational performance’s rationality is of great significance in hospitals’ energy conservation efforts. This study conducted an annual post-occupancy evaluation of a general hospital located in a hot summer and cold winter area in east of China. Two hundred and seventy-eight valid online satisfaction questionnaires, sixty valid point-to-point questionnaires, indoor environment data of each typical season, and energy consumption data were obtained. The overall indoor environment of the selected hospital met the standard requirements. The results showed that occupant satisfaction was influenced by gender, working hours, and length of stay. The annual energy consumption level of this building was 84.7 kWh/m2, which is significantly lower than that of other public general hospitals in China and general hospitals in developed countries. The energy consumption of the inpatient department was directly related to the hospital days, with an increase of 12.2 kWh/m2 for every 1000 additional hospital days. A new indoor environment quality (IEQ) model and a new comprehensive evaluation model for energy efficiency were established. Overall, the outpatient department exhibited superior performance compared to the inpatient department. These evaluation models can help owners and decision-makers in the identification of environmental performance in hospitals.