英语语法分析

Whereas refrigerative systems reduce the humidity of air (because some water vapour condenses and is drained away), evaporative coolers increase humidity.

虽然制冷系统会降低空气的湿度(因为凝结作用会带走部分水蒸气)，但是蒸汽冷却器却能够增加空气湿度。