The critical wind velocity in sloping tunnels will be different from horizontal tunnels due to the stackeffect.
在坡度隧道中，由于火风压的作用，临界风速与水平隧道临界风速相比会有一定的差异。
2
The air then moves up though the space via the stackeffect and is allowed to circulate above interior walls and out through an operable exhaust vent.
然后，空气通过堆栈效应移动，并且可以通过一个排气孔在室内墙壁和外部循环运行。
3
The mechanical option makes use of oversized heat exchangers and low power fans to complement the passive stackeffect already assisting the air movement in the ducts.