Evaluation of Peak Electricity Load Effects from the Application of Sequential Cooling System Operations in Public Office Buildings

The Government of the Republic of Korea has implemented various policies targeting public office buildings to reduce peak electricity load and overall energy use in cooling. During periods of energy and power crises, sequential operation strategies for a cooling system are recommended to lower peak electricity demand in buildings. However, current sequential operations are typically implemented through cooling system shutdowns or arbitrary indoor temperature increases to reduce peak cooling electricity load. This study evaluated the effectiveness of different sequential cooling system operation strategies in public office buildings by analyzing their impact on peak cooling energy load and indoor thermal environment. Through simulation-based analysis, two main control approaches, traditional on/off control and set-back temperature control, were compared. Results demonstrated that while on/off control scenarios achieved a 64% reduction in peak cooling electricity load, these scenarios caused significant thermal discomfort and cooling load spikes upon system restart. In contrast, set-back control scenarios maintained indoor temperatures within the set-point range and reduced peak cooling electricity load by 8.7% while maintaining PMV values within approximately +0.5 compared to the common operation case. The set-back control strategy also prevented sudden cooling load increases observed in the on/off scenarios, offering a more balanced approach to energy management and occupant comfort in public office buildings.