Cooling performance of direct expansion system using multiple stages and adjustable heat exchange areas for fresh air handlingFuhai Zha, Chenjiyu Liang, Lin Fang, Toshio Tanaka, Nobuki Matsui and Xianting LiE3S Web Conf., 672 (2025) 07020DOI: https://doi.org/10.1051/e3sconf/202567207020