Evaluation of Commissioning Benefits by Varying Control Types for Economizer System: Focusing on the operational data of the “H” Building

This study aimed to evaluate the operational appropriateness of an economizer and to analyze its energy performance under different control methods, based on the operational data of an office building located in Seoul. To this end, simulation cases were defined according to the economizer control method, and a simulation was performed for each case. The results showed that, when the economizer was applied, the outdoor air (OA) intake rate was systematically controlled according to the OA conditions and the prescribed control criteria, and that Case #2 (Differential dry-bulb temperature control) exhibited the highest utilization of OA cooling. Analysis of the mixed air conditions indicated that, during the interseason, both the temperature and the absolute humidity decreased, resulting in conditions favorable for cooling, whereas in summer, the absolute humidity tended to increase due to the high humidity of the OA. In addition, the cooling coil load decreased by up to 9.8% during the interseason and by about 2.8% in summer, confirming the energy-saving effect of economizer operation. In particular, Case #2 showed the best energy-saving performance, a result that differs from those of previous simulation-based studies, which mainly suggested enthalpy-based control methods. These findings indicate that the optimal control method may vary depending on the actual operating conditions of a building and highlight the need for control optimization through commissioning based on operational data.