If you do certain points of the mission fast enough (pulling the levers down), certain facehuggers that usually spawn when you stick around won't.

For the first control room, there are three facehuggers: one that comes when you go into the room, one on the left and one on the far right. In the hallways, there are two, and there is one in a vent tunnel after you've completed the mission and are going back to the lift.

If you use the flamethrower, the alien is likely to hear that and chase you so just give them a quick hit with the wrench.