Thermodynamics — Energy & Cycles

The fridge run backwards — coefficient of performance

continues from lesson 4 — values defined earlier in the course stay live here

ELI5: a fridge is an engine in reverse: spend work to move heat from cold to hot. Its COP = T_cold / (T_hot − T_cold) is often well above 1 — you move several joules of heat per joule of work, which is why heat pumps beat resistive heaters.

T_{inside} := 277 K

= 277 K fridge interior (~4 °C)

T_{room} := 297 K

= 297 K kitchen (~24 °C)

COP_{fridge} = \frac{T_{inside}}{T_{room} - T_{inside}}

13.8500

COP ≈ 13.9 (ideal)

✓ pass

COP_{fridge} > 1

more heat moved than work spent — that's the magic of heat pumps