Cold isn't a thing that flows — heat is. It's tiny jiggling, and it always slides ONE way: from warm into cold. The warm hand's heat flows into the ice pop.
See the rule for yourself: tap — the heat dots always drift toward the cool side, never backward. But then how can the AC push heat OUT of your cool room into the HOTTER yard? It needs a trick…
SQUEEZE the gas: it gets hotter, like a bike pump. Let it EXPAND: it cools. The AC uses these changes to make one pipe colder than your room and another hotter than the yard.
Squeeze = hotter jiggle. Expand = colder calm. Same gas, both ways.
The loop uses the rule TWICE. Expanded, the pipe is icy (5°) — colder than your room — so room heat falls IN and rides along. Outside, the SQUEEZE crams it hot (60°) — hotter than the yard — so it falls OUT. Downhill both times!
The room starts at 30°. Run the AC: heat rides the loop outside, and the room cools. Turn it off: the hot day warms the room again. Watch both the room number and the outdoor box.
room 30° — a hot day
In winter, heat escapes from your house. One fix is a FURNACE: a controlled flame MAKES heat from fuel. But each bit of warmth costs energy.
A furnace makes heat. But making it costs a lot of energy…
But option two is sneakier…
Here is a different machine to try: a reversible squeeze-loop. A valve can swap which coil gets squeezed hot and which expands cold. What happens if we reverse it on a freezing day? 🤔
It's a freezing 0° day. We flip the loop backwards.
What happens to the house?
Slide to flip the loop 🔀
