Building Performance & Environmental Systems Lab.

With the growing emphasis on indoor humidity control in energy-efficient buildings, heat-pump-driven liquid- desiccant (HPLD) systems have emerged for their ability to independently control air temperature and humidity. Previous studies have estimated their power consumption using theoretical models, which are often limited by structural complexity and challenges in physical interpretation. Additionally, theoretical models yield prediction inaccuracies when applied to buildings because they lack sensitivity to dynamic environmental variations typically observed in real-building conditions. This study develops a simplified data-driven model using real- building measurements to predict power consumption, capturing partial-load compressor performance under variable outdoor conditions and indoor thermal loads during the summer season. A polynomial regression method is used to develop the model in a simplified equation-based form. The developed model achieves R- squared, root mean squared error, and mean absolute percentage error (MAPE) values of 0.9583, 0.0668, and 8.37 %, respectively, in predicting the partial-load compressor power. Moreover, the model predicts the compressor energy consumption during summer operations with a percentage error of 0.36 %. Its adaptability is further validated against previous studies on HPLD systems with diverse features and specifications, within an acceptable error bound of ±20 % and a MAPE of 11.1 %. These results highlight the exceptional prediction accuracy and practical utility of the model developed in this study, supporting its adoption in various building application scenarios and replacement of theoretical models.

The global demand for space research has surged, driven by advancements in technology and the pursuit of extraterrestrial resource utilization. As the development of lunar resources and infrastructure necessitates a sustained human presence, establishing a lunar habitat is imperative for the long-term advancement of space exploration. To ensure continuous power supply to such a habitat, thermoelectric generators (TEGs), which directly transform heat flux into electrical energy, can be utilized, leveraging the extreme temperature gradient on the lunar surface, which ranges from 90 to 390 K. However, although some studies suggest that the transient- state operation may enhance the TEG efficiency, its feasibility under lunar conditions remains unexplored. Therefore, as switching heat storage (HS) induces the transient state by altering the temperature of the working fluid and HS is generally necessary due to the Moon’s prolonged nights, this study aims to assess the suitability of a multiple-HS system to generate a thermally transient state in the TEG through HS switching. The results showed that the multiple-HS structure increased power generation by approximately 48.9 % under the lunar environment, pointing temperature altering can enhance the power generation of the TEG-based system on the moon. Additionally, the effects of switching timing of multiple-HS and size of HS were assessed, but its impact is relatively low, +0.3 % for switching timing and − 0.5 % for size. The findings should contribute to lunar research, providing insights for the transient characteristics of TEGs.