I see this opportunity for some warmth and it's a large generator sitting in the center of our camp, blowing warm air out of all the exhaust vents and everything.
Because steam is pushing on the piston in one direction and then the other, back and forth, while the opposite side is venting through the exhaust, it is called a double-acting cylinder.
If you've ever wondered what the opening at the end of the fuselage is, you were likely looking at the exhaust for the APU.Air from this small engine is removed constantly as it generates power for the aircraft.