Heat Pump Performance (COP)
The heat emitted by a heat pump is notionally the sum of the heat extracted from the heat source (air, water, solar, ground) and the energy needed to drive the phase.
The performance of an electric compression heat pump at a set temperature condition is referred to as the coefficient of performance (COP). It is defined as the ratio of heat delivered by the heat pump and the electricity supplied to the compressor.
For electrically driven heat pumps, the performance is indicated by the primary energy ratio (PER) and can also be defined, by multiplying the COP with the power generation efficiency.
The COP or PER of a heat pump is closely related to the temperature lift, i.e. the difference between the temperature of the heat source and the output temperature of the heat pump. The COP of an ideal heat pump is determined solely by the condensation temperature and the temperature lift (condensation – evaporation temperature).
Typical COP/PER range for heat pumps with drive energies:
|Heat Pump Type||COP||PER|
|Electric (AquaCal)||2.5 – 5.0|
|Engine||0.8 – 2.0|
|Thermal||#ece9d8; border: #000000 0px solid;”>||1.0 – 1.8|
Factors that Affect Heat Pump Performance
The performance of heat pumps is affected by an array of variables:
- temperatures of the heat source and system distributing the heat
- auxiliary energy consumption (pumps, fans, etc.)
- technical specifications of the heat pump
- sizing of the heat pump as it directly relates to the demand and operating characteristics of the heater itself
- control system of the heater