負壓等如什麼????是什麼原理??????

It is a kind of nomenclature學術用語. Any measurement or numbers deviate from a reference point ( normally set at 0), will be named positive in one direction and negative in the opposite direction.

負壓 = same 壓力 but opposite direction

push = pull in opposite direction = 負pull

真空 = nothing, no 壓

如果係傳染病房,就會把帶病毒的空氣推出房外走廊而令經過的人有機會受感染.所以傳染病房會採用負壓空調系統,即係用抽氣扇抽病房的空氣出街.房外走廊的空氣就會因病房是處於低壓而自動走入去,帶病毒的空氣被抽出室外街道被大量空氣稀釋,危險性相對就低好多.


負壓方式也有應用在冷卻系統方面,原本正壓時會灟水的水喉,在負壓時就唔會灟水.冷郤水道不一定要絶對密封,設計的彈性就會大得多.
Ciao