Vents

"Vents are a great way of avoiding danger, but they may not always be as safe as you think."

- In-game description

Vents are another means of traversing Sevastopol.

Summary
Vents are a means for Amanda Ripley, and other survivors, to traverse Sevastopol without directly coming into contact with hostile enemies. Unfortunately, as many residents have theorized, the creature also travels through the vents. Making Vents a high risk, high reward sort of means of travel. While traveling through the Vents can sometimes be mundane, there are occasionally Items within them. In some cases there are even ID Tags within them alongside unfortunate victims of the creature.

Versions
There are a couple of versions of Vents present in Alien: Isolation. Two are positioned on walls and open automatically when nearby, while the third is positioned on the floor. Requiring Ripley to physically interact with it, before she can enter them.