Air Conditioners Don't Make Cold—They Move Heat: How the Vapor-Compression Cycle Really Works
Do you picture the outdoor unit sucking in fresh air, chilling it, and piping it inside? It doesn't. Indoor air just recirculates within the room—what actually travels between the indoor and outdoor units through the suction and liquid lines is refrigerant, not air, carrying heat out. An air conditioner is a heat pump running the exact same vapor-compression refrigeration cycle as your refrigerator. We trace the thermodynamic principle—compress a gas and it heats up; expand it and it cools down—and uncover why spacecraft burn up during re-entry. Spoiler: it's the same compression heating, not air friction.
