Measurement and Operational Improvement in an Office with Thermo Active Building System

Thermo Active Building System (TABS) is applied in office buildings in many European countries as a promising energy-efficient solution with a comfortable thermal environment. However, TABS is rarely applied in Japanese buildings because of the risk of dew condensation during the hot and humid summer season. In this study, the indoor environment and thermal sensation in an office building equipped with TABS was investigated; the building is located in an urban area in Tokyo, Japan. Soon after occupancy, field measurements and questionnaire surveys were conducted during the summer and winter seasons for two consecutive years. The operation of TABS was improved based on first-year measurement results. As a result, the ceiling surface setpoint temperature was relaxed, maintaining high satisfaction in summer. In winter, it was confirmed that the operation of TABS was not necessary, and, as a result, satisfaction improved.