Air Exchange

The Air Exchange, also known as the "Air Exchange", "AirEx" or "Air Conditioner", is a chapter cut from Half-Life 2. It was set after the Depot, at the end of the Wasteland chapters.

Features
In this chapter, set right after the Depot levels, the player was to meet Captain Vance, Alyx's father and one of the few surviving military leaders. Vance is supposed to protect the place while he is secretly organizing the resistance. A small battle is lead there by Vance and his Conscripts. Gordon must reach the top of the highest tower, then take a plunge into a tiny pool of industrial solvents at its base. The whole place is sabotaged somehow and triggers the human uprising. Gordon then reaches the shore on foot and proceeds to the Borealis.



Fate
Blowing up the AirEx to trigger the uprising was merged with the Depot levels to make the Nova Prospekt levels; reaching the top of the highest tower was recycled in the Citadel levels, as long with the factory-like themes.