noun
negative pressure ventilation fan; exhaust fan
Technical term used in building ventilation and HVAC contexts. Refers to a fan that creates negative pressure to exhaust air.
この部屋には有圧換気扇が設置されている。
A negative pressure ventilation fan is installed in this room.
Compound of 有圧 (yūatsu, 'with pressure') + 換気扇 (kankisen, 'ventilation fan').