Determining the optimal set-point temperature considering both labor productivity and energy saving in an office building

Abstract

To address the trade-off problem between the labor-productivity-enhancing perspective and the energy-saving perspective in office buildings, this study sought to determine the optimal office set-point temperature considering both the labor productivity of an office worker and the heating, ventilation, and air-conditioning (HVAC) energy saving. Towards this end, the labor productivity of an office worker was estimated based on the results of the cognitive tests performed in an environmental chamber, and the HVAC energy demand were calculated using building energy performance simulation conducted on the “Y” office building located in Seoul, South Korea. In addition, integrated multi-objective optimization was used to suggest an optimal indoor set-point temperature that can solve the trade-off problem between the energy-saving perspective and the labor-productivity-enhancing perspective. The results showed that the maximum productivity of an office worker occurred at an indoor set-point temperature of 25.15 °C. The analysis revealed that the total HVAC energy demand showed a tendency to decrease as the cooling set-point temperature increased, but the heating set-point temperature decreased. It was also found that the optimal set-point temperature varied depending on the hourly and monthly weather conditions. In addition, the trade-off relationship in which the energy saving ratio decreases as the labor productivity increases was confirmed through experiments. Therefore, it is expected that the findings of this study will help policymakers establish a system for optimal set-point temperature standards for office buildings that can solve the trade-off problem between the energy-saving perspective and the labor-productivity-enhancing perspective.