The thermal comfort of occupants in the increasing number of modern buildings with glass curtain wall structures is of significant research interest. As the thermal sensitivity of building occupants varies with building features, situational factors, and the human body’s thermal balance, it is necessary to derive the comfort temperature based on field research, which was conducted in this study in a South Korean office building with a glass curtain wall structure. The influence of solar radiation on the indoor thermal environment and thermal comfort obtained by measurements and occupant questionnaires was analyzed using cumulative graphs and a sensitivity analysis. The observed changes in operative temperature over time confirmed that occupant comfort was significantly affected by the radiant temperature. Based on this result, two groups (Group A near the windows and Group B near the interior corridor) were defined for analysis. Owing to the influx of solar radiation, Group A was more sensitive to changes in the thermal environment (0.67/°C) than Group B (0.49/°C), and the derived comfort temperature for each group differed from the set temperature by approximately ±2 °C. Thus, it was confirmed that the solar radiation introduced through a glass curtain wall building has a direct impact on the indoor thermal environment and occupant comfort according to location.

The world is emphasizing the need for building design that considers energy performance to deal with climate problems. South Korea has constantly been tightening the design standards for saving building energy but with a focus on thermal performance and equipment systems. Accordingly, this study conducted an energy simulation experiment on office buildings with different window-to-wall ratios (WWRs) to propose a smart glazing plan to improve energy performance. An energy simulation experiment was performed on office buildings with varying WWRs to hierarchically analyze the influence of building window performance elements, including the heat transmission coefficient (U-value), visible light transmittance (VLT), and solar heat gain coefficient (SHGC), on building energy performance. The analysis showed that SHGC had the most significant impact on the heating and cooling load, by 22.13%, with the influences of the variables being 12.4% for the U-value, 4.78% for VLT, and 82.83% for SHGC. The results showed that the solar heat gain coefficient (SHGC) had the greatest impact on energy performance among window performance elements, and the effect increased significantly in certain WWRs. Moreover, to improve the energy performance of buildings with higher WWRs, it is essential to reflect the optimum composition of the U-value and SHGC on the window plan. This study’s findings propose measures to supplement existing window plans focusing on thermal performance. Furthermore, these results hold academic value in providing concrete grounds for that.

In the residential sector, householders play an active role in regulating the indoor climate via diverse control measures such as the operation of air-conditioners or windows. The main research question asked in this paper is whether control decisions made by householders are rational and effective in terms of achieving comfort and energy efficiency. Based on a field study in South Korea, this paper explores how a HVAC control strategy for high-rise apartment buildings can affect occupant comfort and adaptive behavior. Two different control strategies: (1) occupant control (OC), where occupants were allowed to freely operate the HVAC system and (2) comfort-zone control (CC), where the operation of the HVAC system was determined by the researcher, based on a pre-defined comfort zone, were applied to, and tested within the participating households in summer. The impact of the two control strategies on indoor thermal environments, thermal comfort, and occupant adaptive behavior were analyzed. We find that the CC strategy is more energy/comfort efficient than OC because: (1) comfort was be achieved at a higher indoor temperature, and (2) unnecessary control behaviors leading to cooling load increase can be minimized, which have major implications for energy consumption reduction in the residential sector.

The control that have the greatest influence on comfortable in the office occupants are the heating, ventilation, and air conditioning (HVAC) system operation and the thermal environment. However, comfortable HVAC operation is difficult in the office space characterized by a recommended standard thermal environment or a centralized HVAC system. To consider the occupant's thermal comfort to the greatest possible extent, must establish a method to quantify the variables related to the occupant’s thermal comfort. This study aims to group occupants in Thermal sensation vote (TSV) clusters and perform sensitivity analysis (SA) on the relationship between thermal environmental factors in an office building and each cluster’s TSV to establish the typology of the control indicators for each cluster. A total of 10 field experiments were conducted in the same office. This field study was carried out 2022. The indoor thermal environmental parameters, the subjective evaluation of the thermal comfort of the resident and the operation pattern of the heating system were monitored at the same time. A total of 4,200 datasets related to indoor thermal environmental parameters and a total of 1,680 datasets related to occupants’ thermal comfort were collected and analyzed. The results of this study show that people have different levels of adaptability and sensitivity to a given thermal environment. This study founded distinguishable similarities in their thermal sensation traits and grouped similar TSV values into five clusters that responded differently to the same thermal environment. Each cluster showed different TSV and Thermal comfort vote (TCV) patterns, which allowed us to classify the groups that had sensitive responses to the thermal environment and those that did not. This study was determined different control indicators and guidelines for the divided groups according to thermal sensitivity.