❄️ Refrigeration COP & Chiller Performance

Chiller & Cooling Sizing Overview

In refrigeration engineering, HVAC design, and cold chain logistics, the efficiency of chillers is measured using the **Coefficient of Performance (COP)**. COP represents the ratio of the cooling capacity extracted at the evaporator to the electrical power consumed by the compressor motor.

Optimizing COP requires minimizing the temperature difference between the condenser and the evaporator, utilizing highly efficient compressors, and ensuring proper refrigerant flow rates. This page links to our thermodynamics vapor-compression cycle solver to run performance rating evaluations.

Mathematical Formulation

1. Coefficient of Performance ($COP_R$)

$$COP_R = \frac{\text{Cooling Capacity}}{\text{Compressor Work Input}} = \frac{Q_L}{W_{in}}$$

For an ideal vapor-compression refrigeration cycle:

$$COP_R = \frac{h_1 - h_4}{h_2 - h_1}$$

Where:

• $h_1$ = Enthalpy at evaporator exit (compressor inlet) [kJ/kg]
• $h_2$ = Enthalpy at compressor exit (condenser inlet) [kJ/kg]
• $h_4$ = Enthalpy at expansion valve exit (evaporator inlet) [kJ/kg]

2. Energy Efficiency Ratio (EER)

Commonly used in US air-conditioning ratings, expressing cooling capacity in BTU/h and electrical power in Watts:

$$EER = 3.412 \cdot COP_R$$

3. Carnot COP (Theoretical Limit)

The maximum possible thermodynamic efficiency for a chiller operating between evaporator temperature $T_L$ and condenser temperature $T_H$ (both in Kelvin):

$$COP_{Carnot} = \frac{T_L}{T_H - T_L}$$

Related Applications

• ⚡ Steam System Properties
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