The Ventilation Shaft is a room in the Phazon Mines. It connects the Elite Control to the Omega Research by White Doors.
The room is essentially a large rounded tunnel, with a fan at one end. The door to the Elite Control is located high on the side of the room, so once Samus jumps down, she must use the room as a Half Pipe to get back up.
When Samus first enters the room, Puffers will begin to come out of holes in the ceiling, as well as flooding the room with damaging gas. A maximum of five will be in the room at one time, but every time one is destroyed, another will come out. When Samus returns with the Power Bombs, she can open a small grate on the floor to reveal a small Morph Ball tunnel. This tunnel leads to a side room that has a Scan Terminal. This terminal activates the fan at one end of the room. This fan will push the Puffers into the far wall, destroying it to reveal an Energy Tank. This will also get rid of the gas and prevent Puffers from appearing in the room.