Performance characteristics of a waste-heat recovery water-source heat pump system designed for data centers and residential area in the heating dominated region

Data centers (DCs) have been increasingly constructed owing to the increasing demand for data storage. The performance of the cooling system for DCs should be improved for energy saving owing to a large amount of energy consumption for cooling. A residential area (RA) consumes a large amount of energy for heating, especially in the heating dominated region. A novel waste-heat recovery water-source heat pump (WSHP) system is proposed for the combination of the DC and RA to reduce energy consumption by recovering waste heat from the DC and to suppress the freezing risk of water during the heating season. The performance characteristics of the waste-heat recovery WSHP system were analyzed based on various perspectives including energy consumption and environmental impact. Consequently, the annual average power usage effectiveness for the DC and the system coefficient of performance for the RA showed a significant improvement compared to the conventional system; accordingly, the energy consumptions of the DC and RA decreased by 12.3% and 31.2%, respectively. The energy consumption of the DC decreased by 64.4% in March, and that of the RA reduced by 48.2% during the heating season, which led to an 18.8% decrease in total annual energy consumption of the proposed system. Additionally, the risk of freezing in the evaporator of the WSHP was substantially suppressed under cold winter conditions, increasing the system reliability; the water temperature at the evaporator outlet was maintained at 8–12 °C owing to the waste heat absorbed from the DC. Based on the lifecycle climate performance (LCCP) analysis, the proposed system showed a 28.7% reduction in total CO2 emissions compared with the conventional system. The proposed system can be a good option for reducing the energy consumption and for enhancing system reliability through the combination of the DC and RA.