Vent Mod is an addition to Black Mesa's "We've Got Hostiles!" chapter, adding new areas to the last bits of the chapter. This mod re-adds and revamps the vent sections of the chapter, which were cut from Black Mesa due to their inadequacies. The issues that they had in the original have been (hopefully) done away with.
[NEW] EDIT: I have looked at the bullet holes used later in the game, and they look around the same so I guess they don't really need improving. Better than to have them then not. Also, the vortigaunt and headcrabs don't always spawn as you're making your way back after being in the dead female scientist area. The reason is that the trigger is tied to the suit battery in the elevator which you don't always need. Also, the headcrab that jumps out of the vent needs to turn around once it lands. It never actually sees you unless you get close/fire at it. Additionally, after playing the newest update, I have found one more issue and have had another idea for an improvement. First, I believe you took my advice and added the red lights to some vents, as I don't remember them from my original playthroughs. However, they don't emit light in this version. I believe you would need to put light entities in or around the lights, but I'm not sure how the BMS team did it. Also, I see you took my recommendation of having the zombie bang his head on the wall, and it looks great. But you might want to make it so that you trigger his attention when you take a couple steps into the hallway, as he now never notices you at all. Also, just an idea: To the left of the zombie that was added at the end (who kills the guard in the beginning), swap the blue metal crate that's there with one of the blue pushable ones found in Office Complex so that it is easy to climb into the vent from that side, and add some props on top/around it to remove some of the emptiness of the hall . Also, put some guard gibs in the vent itself to show that the zombie killed the guard, and make the scientist say something when he opens the door. As a bonus, you could also fix the same zombie in the beginning of the chapter, as when he grabs the guard, the zombie doesn't go far enough into the vents and you can see his head disappear when the event ends. Still, some very nice improvements overall in the new version!
It's a bit short, but I say it's a valuable addition to the We've got Hostiles! chapter. An update here and there would also be welcome, but I'm alredy satisfied. Well done!