IJLTEMAS International Journal of Latest Technology in Engineering, Management & Applied Science (IJLTEMAS) IJLTEMAS 2278-2540 IJLTEMAS 251 10.51583/IJLTEMAS.2026.150800057 Education Assessment of Thermal Performance of Modular Wall Panels with Salt Hydrate PCMS in Selected Classrooms of Gusaling Villegas in Pamantasan NG Lungsod NG Maynila Zedrick P. Aguilar, Pamantasan ng Lungsod ng Maynila, Faculty Member Philippines Marc Nel G. Glomar, Pamantasan ng Lungsod ng Maynila, Faculty Member Philippines Erron N. Icamina, Pamantasan ng Lungsod ng Maynila, Faculty Member Philippines Xaviel Wei Zhi. Lai, Pamantasan ng Lungsod ng Maynila, Faculty Member Philippines Rumil Angelo M. Magaling, Pamantasan ng Lungsod ng Maynila, Faculty Member Philippines Algerico Jr S. Odal, Pamantasan ng Lungsod ng Maynila, Faculty Member Philippines 15 8 816 828 20 08 2026 25 08 2026 10 09 2026 phase change materials; salt hydrate PCM; passive cooling; thermal performance; classroom; thermal comfort Abstract

Classroom overheating is an increasing concern in tropical urban environments, particularly in educational buildings where elevated indoor temperatures may affect thermal comfort and learning conditions. This study evaluated the thermal performance of modular wall panels integrated with salt hydrate phase change materials (PCMs) as a passive cooling intervention in selected classrooms of Gusaling Villegas (GV) at Pamantasan ng Lungsod ng Maynila. A quasi-experimental research design was employed using one classroom equipped with PCM-integrated wall panels as the test room and another classroom without PCM panels as the control room. Indoor temperature and relative humidity were monitored over six testing days. The PCM system utilized sodium sulfate decahydrate as the salt hydrate PCM, with polyethylene terephthalate (PET) bottles serving as the protective encapsulation material. Differential scanning calorimetry testing was also conducted to examine the thermal characteristics and repeatability of the PET casing material. The results showed that the PCM-equipped classroom consistently recorded lower temperatures than the control classroom. Mean temperature differences across the six testing days ranged from 0.14°C to 0.67°C, while the maximum observed peak-temperature reduction was 0.85°C. The largest average temperature reduction occurred under the hotter conditions observed on Day 5. Relative time-lag effects were inconsistent, with measurable delays observed on some testing days but no consistent delay across the entire monitoring period. Relative humidity was only marginally affected, with an overall average difference of approximately 0.98%. Statistical analysis showed that the temperature data were non-normally distributed; therefore, a Mann–Whitney U test was employed. The test indicated a statistically significant difference between the temperature distributions of the test and control rooms (p < 0.05), with the PCM-equipped room exhibiting a lower mean temperature. Despite the statistically significant difference, the magnitude of temperature reduction remained relatively small for practical thermal-comfort improvement. The findings indicate that PCM-integrated wall panels have measurable passive-cooling potential but require improved encapsulation, thermal conductivity, surface-area-to-volume ratio, placement, and experimental duration to maximize their effectiveness in existing educational buildings.

 References Akkose, G., Akgul, C. M., & Dino, I. G. (2021). Educational building retrofit under climate change and urban heat island effect. Journal of Building Engineering, 102294. https://doi.org/10.1016/j.jobe.2021.102294 Auliciems, A. & Szokolay, S.V. (2007) Thermal Comfort, 2nd ed.; Passive and Low Energy Architecture International in association with Department of Architecture, The University of Queensland: Brisbane, Australia, Alam, T. E. (2015). Experimental Investigation of Encapsulated Phase Change Materials for Thermal Energy Storage. USF Tampa Graduate Theses and Dissertations. https://digitalcommons.usf.edu/etd/5632 Alassaad, K., Minto, J., & De Wilde, P. (2025). Enhancing Building Thermal Performance: A Review of Phase Change Material Integration. Energies. Enhancing Building Thermal Performance: A Review of Phase Change Material Integration. Ayyagari, V., Shooshtari, A., & Ohadi, M. (2025). Glauber’s Salt Composites for HVAC Applications: A Study on the Use of the T-History Method with a Modified Data Evaluation Methodology. Materials, 18(13), 2998. https://doi.org/10.3390/ma18132998 Baetens, R., Jelle, B. P., & Gustavsen, A. (2010). Phase change materials for building applications: A state-of-the-art review. Energy and Buildings, 42(9), 1361–1368. https://doi.org/10.1016/j.enbuild.2010.03.026 Bharathiraja, R., Ramkumar, T., Selvakumar, M., & Radhika, N. (2024). Thermal characteristics enhancement of Paraffin Wax Phase Change Material (PCM) for thermal storage applications. Renewable Energy, 222, 119986. https://doi.org/10.1016/j.renene.2024.119986 Chaichan, M. T., Kazem, H. A., Al-Waeli, A. H. A., & Sopian, K. (2021). Controlling the melting and solidification points temperature of PCMs on the performance and economic return of the water-cooled photovoltaic thermal system. Solar Energy, 224, 1344–1357. https://doi.org/10.1016/j.solener.2021.07.003 Cui, Y., Gulfam, R., Ishrat, Y., Iqbal, S., & Yao, F. (2024). Recent Progress of Phase Change Materials and Their Applications in Facility Agriculture and Related-Buildings—A Review. Buildings, 14(9), 2999–2999. https://doi.org/10.3390/buildings14092999 Cui, Y., Xie, J., Liu, J., Wang, J., & Chen, S. (2017). A review on phase change material application in building. Advances in Mechanical Engineering, 9(6), 168781401770082. https://doi.org/10.1177/1687814017700828 Daanoy, S. (2024, April 1). 87% of Metro Manila teachers say classroom heat hinders effective teaching, learning — survey. Manila Bulletin. https://mb.com.ph/2024/4/1/87-of-metro-manila-teachers-say-classroom-heat-hinders-effective-teaching-learning-survey Duan, R., Wang, J., & Zhang, A. (2024). Analysis of thermal stability and enthalpy in SSD systems with various thickening agents. Journal of Physics: Conference Series, 2842(1), 012033. https://doi.org/10.1088/1742-6596/2842/1/012033 Estoque, R. C., Ooba, M., Seposo, X. T., Togawa, T., Hijioka, Y., Takahashi, K., & Nakamura, S. (2020). Heat health risk assessment in Philippine cities using remotely sensed data and social-ecological indicators. Nature Communications, 11(1), 1581.https://doi.org/10.1038/s41467-020-15218-8 Guarnieri, G., Olivieri, B., Senna, G., & Vianello, A. (2023). Relative Humidity and Its Impact on the Immune System and Infections. International Journal of Molecular Sciences, 24(11), 9456. https://doi.org/10.3390/ijms24119456 Faghih, N., Mahdieh Abravesh, M., & Heidari, S. (2023). Investigation of effective parameters on thermal performance of multilayered glazing units integrated with Phase Change Material. https://doi.org/10.13140/RG.2.2.21360.02561 Harris, A. D., McGregor, J. C., Perencevich, E. N., Furuno, J. P., Zhu, J., Peterson, D. E., & Finkelstein, J. (2006). The Use and Interpretation of Quasi-Experimental Studies in Medical Informatics. Journal of the American Medical Informatics Association, 13(1), 16–23. https://doi.org/10.1197/jamia.m1749 He, S., Zhao, J., Ouyang, D., & Chen, M. (2025). Leakage-Proof and High-Conductivity Composite Phase Change Material Using Low-Melting-Point-Alloy-Encapsulated Copper Foam/Paraffin for Superior Thermal Homogeneity in Lithium-Ion Battery Modules. Materials, 18(19), 4604. https://doi.org/10.3390/ma18194604 Hirschey, J., Gluesenkamp, K., Mallow, A., & Graham, S. (2018). Purdue ePubs Review of Inorganic Salt Hydrates with Phase Change Temperature in Range of 5 to 60°C and Material Cost Comparison with Common Waxes. https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1319&context=ihpbc Huet, E. E. (2016). Experimenting with refrigerated margarine as phase change material and zeolite as desiccant for temperature and humidity control in Philippine archives. Journal of Philippine Librarianship, 36, pp. 1-14. https://journals.upd.edu.ph/index.php/jpl/article/view/5942. Jin, X., Xu, X., Zhang, X., & Yin, Y. (2014). Determination of the PCM melting temperature range using DSC. Thermochimica Acta, 595, 17–21. https://doi.org/10.1016/j.tca.2014.09.004 Jobli, M. I., Yao, R., Luo, Z., Shahrestani, M., Li, N. and Liu, H. (2019) Numerical and experimental studies of a capillarytube embedded PCM component for improving indoor thermal environment. Applied Thermal Engineering, 148. pp. 466477. https://doi.org/10.1016/j.applthermaleng.2018.10.041 Naidoo, N. (2020). Classroom temperatures in urban and rural classrooms: disparities that hinder a just energy transition and opportunities for interventions. The Pan African Medical Journal, 53(98). https://doi.org/10.11604/pamj.2026.53.98.49674.