How to use the Refrigeration COP Calculator
- 1. Choose your dataEnthalpies from the chart, capacity and power, or the two temperatures.
- 2. Enter valuesh1, h2, h4 in kJ/kg, or capacity in TR or kW and the power input.
- 3. Read the COPCOP, heat pump COP, EER and, with capacity, mass flow and compressor power.
COP formulas
COP of a refrigerator = heat removed / work input. For the vapour compression cycle: refrigerating effect RE = h1 − h4, compressor work W = h2 − h1, so COP = (h1 − h4) / (h2 − h1). Throttling is isenthalpic, so h4 = h3.
Refrigerant flow = capacity / RE, and compressor power = flow × W. 1 TR = 211 kJ/min = 3.5167 kW. The ideal limit is the Carnot COP = TL / (TH − TL) in kelvin.
Worked example and exam tips
A cycle has h1 = 395, h2 = 425 and h4 = 255 kJ/kg. RE = 140 kJ/kg, W = 30 kJ/kg, COP = 4.67. For a 1.5 TR unit: capacity = 5.275 kW, flow = 5.275 / 140 = 0.0377 kg/s, compressor power = 0.0377 × 30 = 1.13 kW.
- Read h1 at the evaporator exit (saturated or superheated vapour) and h3 at the condenser exit.
- Heat pump COP = refrigerator COP + 1 for the same cycle.
- Lower condenser temperature or higher evaporator temperature raises COP.
Frequently asked questions
What is a tonne of refrigeration?
The cooling needed to freeze one tonne of water at 0 °C in 24 hours, taken as 211 kJ/min or about 3.517 kW.
Can COP be more than 1?
Yes. A refrigerator moves heat instead of making it, so it usually removes several units of heat per unit of work.
What is EER?
Energy efficiency ratio in Btu/h per watt. EER = COP × 3.412.
Is this calculator free?
Yes. You enter your name and WhatsApp number once to see your result, and all other Uncodemy tools then open without the form. Everything is calculated in your browser.