https://doi.org/10.6110/KJACR.2026.38.10.531

Jinhwan Oh ; Yujin Nam ; Kyungjin Bae ; Ohkyung

This study the energy performance and economic feasibility of a glass greenhouse heating and cooling system waste heat from an incineration plant. A dynamic energy simulation model was based on an actual greenhouse in Boseong, Korea. The waste heat an absorption was compared a conventional system an air source heat pump (ASHP) and a boiler. The that the waste heat utilization system annual electricity consumption from 193,517 kWh to 135,054 kWh, energy the total annual energy cost was by 32.57% compared the conventional system, with a maximum reduction of 40.31% depending on operating conditions. These results that waste heat from an incineration plant can significantly the energy efficiency and economic of greenhouse systems.

https://doi.org/10.6110/KJACR.2026.38.10.537

Jikyum Kim ; Jinkyun Cho ; Joo Hyun Moon ; Hoseung Han ; Seongho Kim ; Ha Neol Kim

This study evaluates the energy performance and thermal stability of an immersion-cooled data center system under realistic operating conditions. A system-scale experimental facility two 40 kW immersion cooling providing a total IT load of approximately 80 analysis and PUE were The system a plate heat exchanger the primary chilled-water loop from the secondary dielectric oil loop andoperated under a single-chiller condition. Power consumption and inlet/outlet temperatures were measured at 10-second intervals over two hours, during which the PUE remained within range of 1.1.28. CFD simulations were performed for a single server installed in the immersion cooling tank, nine of 440 W each, all heat source temperatures below 85°C. These results indicate that immersion cooling can achieve both high energy efficiency and reliable thermal management in high-density data center environments.

https://doi.org/10.6110/KJACR.2026.38.10.547

Chan Kyu Kim ; Min Gyu Bang ; Ji Woong Jeong ; Seung Hyo Baek ; Myoung Souk Yeo

Radiant floor heating systems with thermal mass can reduce indoor temperature fluctuations; however, thermal lag may delay reaching the target temperature and lead to inefficient operation. Although heat spreader plates such as aluminum panels have been proposed to enhance heat transfer performance, their effectiveness in radiant floor heating systems with thermal mass has not been sufficiently investigated. This study investigates the heat transfer performance and effectiveness of a heat spreader plate in a conventional radiant floor heating system through building energy simulations. The results show that the use of a heat spreader plate improves heat transfer performance, reducing the time required to reach the target indoor temperature by approximately 12-14%. Under on-off control conditions, differences between the systems with and without the heat spreader plate were small during high heating load periods. However, under low heating load conditions, the system with the heat spreader plate showed longer heating cycles during which the indoor temperature remained outside the deadband. In addition, for equivalent indoor thermal conditions, the system with the heat spreader plate required a lower supply water temperature. These results indicate that the heat spreader plate can enhance overall system and heat source efficiency by enabling operation at lower supply water temperatures.

https://doi.org/10.6110/KJACR.2026.38.10.557

Jae Baek Heo ; Sang Hoon Park

Conventional vapor-compression refrigeration systems condensate during operation; however, in dry the low dew-point temperature limits the amount of To this atmospheric water condensation organic a conventional vapor-compression refrigeration system has been quantitative assessment of moisture condensation under varying temperature and relative humidity conditions is for evaluating its performance. This study established a simulation model to quantitatively the water condensation rate and analyzed the amount of water condensed under psychrometric conditions. The simulation results that the water condensation rate decreased as the outlet air temperature increased, the a sufficiently low cooling coil temperature. even difference in humidity ratio per unit dry air (Δw)the total condensed water increased with a higher dry-air mass flow rate. study condensation performance under a single-cycle condition. circulation cycle the outlet air to the inlet to determine control strategies for achieving target water recovery.

https://doi.org/10.6110/KJACR.2026.38.10.569

Jeong Woo Kim ; Jin Sub Kim ; Jae Hwan Shim

An experimental study was conducted on cooling performance of an adsorption heat pump (chiller) using water as working fluid for low-temperature waste heat utilization. A finned-tube heat exchanger was coated with a metal?organic framework (MOF) adsorbent and integrated into an adsorption heat pump system. The system was experimentally evaluated using low-grade waste heat as the desorption heat source, while cooling energy generated at the evaporator was utilized to assess cooling performance. Performance tests were conducted under various operating conditions, and the system performance was quantified in terms of specific cooling power (SCP) and coefficient of performance (COP). The experimental results confirmed that the adsorption heat pump system using a MOF-coated finned-tube heat exchanger can stably produce chilled water at 20 °C even at a desorption temperature of 50 °C. Based on these results, the proposed configuration shows potential for application in cooling systems utilizing low-temperature waste heat, such as data centers, photovoltaic power generation, and other waste-heat-producing facilities.