On an absorption refrigeration processes the COP (coefficient of performance) is used to define the efficiency of the process. It is the ratio between the produced refrigeration capacity and the hot temperature heat input.

The COP of an ammonia absorption refrigeration plant depends on the three temperatures that define the process:

  1. The heat source temperature, usually between 75°C and 200 °C, may be steam, hot water or any other fluid with a sufficiently high temperature.
  2. The heat sink temperature, usually the cooling water temperature is in a range of 10°C to 35°C.
  3. The evaporation temperature, as the process uses ammonia as refrigerant, is normally between 0°C and -60°C.

The electric energy needed to drive the solution pump is in the range of 1 – 2 % of the heat consumption and is not taken into account on the calculation of the COP.