A "performance gap" arises when the actual value of building energy consumption during the operational phase deviates from the value predicted using simulation during the design phase. One cause of this performance gap is that operation is not ideal, as assumed in the simulation, and the control of the heating, ventilating, and air conditioning (HVAC) system is not optimized. These problems occur because the operator has not been trained sufficiently and/or the building automation system is not working as intended by the developer. Both problems are fundamentally caused by the fact that the quality of building operation cannot be quantitatively evaluated by comparison with other buildings because a building is a heterogenous, single-item product. To address the performance gap problem, we developed a method for quantitatively evaluating building operation using a precise simulation based on a thermal environment emulator. The emulator software was developed using the BACnet protocol as an interface to the real world and includes an occupant behavior model to enable the assessment of operation in terms of thermal comfort as well as energy performance. In this paper, we report on the program and network structure of the proposed emulator. In addition, we show the concrete results of changing the operational control, and we assess changes in energy performance and comfort from the perspective of Pareto efficiency.

The World Championship in Cybernetic Building Optimization (WCCBO) was held in 2019 to test participants' ability to optimize buildings cybernetically. Office buildings with a total floor area of 10,000 m 2 were built in cyberspace, one for each of the 33 participating teams. The cyber buildings were controlled by BACnet, and the participants competed to show their operational skills by tuning the HVAC system of their respective cyber buildings online. The ability of optimization was evaluated in terms of both energy consumption and thermal comfort, and their scores were published online in real-time. A total of 339 different operations were tested during the two-month competition period. The top-ranked team succeeded in reducing energy consumption and thermally dissatisfied occupant rate by 12.1% and 21.0%, respectively. In this paper, we report on the examination of the rules and schedule of this championship as well as the analysis of the participants' scores.

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In this study, we first developed a model using the measured values of the building thermal mass storage system installed in an office building in Tokyo. By comparing the calculated result of this model with the results from the convection air conditioning system model, the differences in the thermal environment of the room and energy consumption were verified. If the water transfer factor at the time of thermal storage is not extremely low, the energy consumption of the building thermal mass storage system is lower than that of the convection system.

Journal of Architecture and Planning (Transactions of AIJ). This paper is based on the translation of the Japanese version with some slight modifications.