COVID-19 drives shifts in groundwater heat pump system operation and groundwater response: Case study on a university library, South Korea

The COVID-19 outbreak caused significant lifestyle changes that affected building energy consumption, with heating and cooling systems as the dominant contributors. Groundwater heat pump (GWHP) systems have emerged as energy-efficient alternatives; however, their operation requires careful management due to potential environmental impacts. Despite growing interest in GWHP systems, long-term monitoring studies remain limited, and few studies have explored the effects of unforeseen events like COVID-19 on GWHP performance. This study presents a detailed long-term investigation of the operational and environmental impacts of pandemic-related changes on a standing column well, a type of GWHP system installed in a university library in South Korea. Continuous operational data collected from September 2017 to December 2023 were analyzed to compare system behavior before and after the pandemic. Hierarchical clustering of over 2000 daily load profiles revealed six heating and five cooling operational patterns linked to occupancy levels and social distancing measures. During the COVID-19 period, high-load clusters decreased by 1% in heating and 13% in cooling, reflecting reduced thermal demand. As a result, thermal imbalance intensified, with the groundwater thermal imbalance ratio shifting from –17.30% before COVID-19 to –58.40% during the pandemic, indicating that the magnitude of the imbalance increased by approximately 3.4 times. These findings provide compelling evidence that pandemic-induced changes directly reshaped both system performance and aquifer conditions. The results provide a practical reference for adaptive operational strategies in GWHP systems and concise guidance for policymakers seeking to enhance energy resilience, support carbon neutrality, and promote sustainable groundwater utilization. • This study analyzes six years of SCW system data in a university library. • The dataset covers pre-, during-, and post-COVID-19 periods. • Clustering identified six heating and five cooling load patterns. • Cooling demand declined and thermal imbalance intensified during COVID-19. • Thermal imbalance increased markedly, by approximately 3.4 times, during COVID-19.