Sitorus, Tulus Burhanuddin, Syahrul Abda, and Terang Ukur Hidayat Solihin Ginting Manik. 2022. “The Earth-Air Heat Exchanger System Performance Combined With a Solar Collector for Cooling an Indoor Space Room in Medan City”. International Journal of Integrated Engineering 14 (6): 146-55. https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/8460.