HomeCalculatorsReverse-Carnot COP (Theoretical Limit)

Reverse-Carnot COP (Theoretical Limit)

Maximum possible cooling COP for a given evaporator and condenser temperature pair. Real cycles achieve 35–65 % of this.

RefrigerationCarnot
Reverse-Carnot COP (max)
4.78 -
Temperature lift
55.0K

Formula, assumptions, and limits

$$\text{COP}_\text{Carnot} = \frac{T_\text{cold}}{T_\text{hot} - T_\text{cold}}$$

Temperatures in kelvin. Practical refrigerant cycles reach 35–60 % of Carnot depending on cycle losses, pinch-point design, and compressor efficiency. Lift of 60 K → Carnot ~4.4 at 0 °C evap.

Symbol legend

SymbolMeaningUnitSource
$T_\text{cold}$Evaporator temperatureKT_evap + 273.15
$T_\text{hot}$Condenser temperatureKT_cond + 273.15

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