排はい煙えん口こう

noun

smoke outlet; smoke vent

Technical term for an opening designed to let smoke escape, used in building ventilation, fire safety, and industrial contexts.

• 火か災さい時じに排はい煙えん口こうが自じ動どうで開ひらく設せっ計けいになっている。

  The smoke vent is designed to open automatically in the event of a fire.