通风橱Fume hood

排风机在橱内形成负压，使室内空气从前窗开口持续流入，携带污染物经顶部风道排出室外。面风速一般要求约 0.4–0.6 m/s：过低不能有效捕集污染物，过高会在窗口形成湍流反而使气体逸出。内部导流板使空气在台面、中部和顶部均匀排出。

The exhaust fan keeps the hood at negative pressure, so room air flows steadily in through the opening and carries contaminants out through the duct. Face velocity is usually set around 0.4–0.6 m/s: too low and contaminants escape capture, too high and turbulence at the opening pushes them out. Baffles draw air evenly from the work surface, middle and top.

操作时前窗尽量放低（通常不超过标示的安全高度），人站在窗外，头不要伸入橱内；实验装置放在距窗口至少 15 cm 处；不要在橱内堆放大量杂物阻挡气流；不能把通风橱当作试剂柜长期储存化学品；使用高氯酸需专用通风橱（防止高氯酸盐在风道中积累爆炸）；氢氟酸、放射性物质等也有专门要求。

Keep the sash as low as practical, below the marked safe height, stand outside and keep your head out; place apparatus at least 15 cm inside the opening; do not clutter the hood and block airflow; do not use it as chemical storage; use a dedicated hood for perchloric acid, whose salts can build up and explode in ducts; and follow special rules for hydrofluoric acid and radioactive materials.

早期实验室依靠烟囱排除炼金和加热产生的烟气。19 世纪末开始出现带玻璃窗的通风柜，20 世纪中叶在大学和工业实验室普及。现代还有变风量通风橱（节能）、无管道过滤式通风橱和生物安全柜（用于病原微生物，带 HEPA 过滤，用途不同）。

Early laboratories relied on chimneys to carry away fumes from alchemy and heating. Glass-fronted hoods appeared in the late nineteenth century and became standard in universities and industry by the mid-twentieth. Today there are energy-saving variable-air-volume hoods, ductless filtered hoods and biological safety cabinets, which use HEPA filters for pathogens and serve a different purpose.