What is the COP of a heat pump?

An air-water heat pump is a highly efficient and economical aerothermal heating solution. Thanks to these capacities, it provides heat for thw whole home. In this article, you will find out what a COP is for a heat pump and the value of the COP of an air-to-water heat pump.

Meaning of the COP of a heat pump

The COP or Coefficient of Performance gives a value requiring a calculation.

Coefficient of Performance or COP

This performance indicator shows the difference between the energy supplied and the energy used in the house. The COP only applies to thermodynamic devices in the heating mode of operation, and the energy performance of the heat pump is reflected in this indicator.

Role of a heat pump

A heat pump captures the energy present in the air, ground, or water using a refrigerant and returns it as heat used to the warm up your water. The rich energy given by a heat pump enables the heat pump to provide heat and domestic hot water.

Calculating the performance factor for a heat pump

The calculation of the COP must be done in a laboratory. The operation consists of knowing the difference between the energy supplied by the heat pump and the electricity used to run the compressor.

In short, COP = amount of energy produced / electricity consumed.

For example: assuming that 1 kWh of electricity is used and a heat pump produces 4 kWh of heat, the heat pump will have a COP value of 4.

Note: the higher the coefficient of performance, the less energy the heat pump consumes.

The capacity of an air-to-water heat pump COP

The average COP value of an air-to-water heat pump is about 3. This value changes typically depending on the outdoor temperature but also the parameters of the device. A heat pump with an annual COP value of 3.5 is regarded as efficient and economical.

What does the COP of an air-to-water heat pump depend on?

The COP of an air-to-water heat pump is based on the outdoor temperature. Generally, the COP should also be high if the outdoor temperature rises. The COP of the heat pump varies according to :

The design of the air-to-water heat pump,
The type of installation performed,
The thermal insulation of the house.

Note: it is recommended to have an air/water heat pump that usually indicates a COP of more than 2.

minimum australian temperatures july — Source:energyrating.gov.au

Interpretation of the COP of the air-to-water heat pump

The COP of a heat pump, which indicates 4, gives 4 kWh of heat-generating energy for 1 kWh of electric current used with water already heated to a temperature of 35 °C.

Generally, the heating equipment helps to achieve an energy saving of 3 kWh. It is essential to point out that this value is valid if the temperature outside is above 7 °C. The COP will decrease as the temperature outside decreases. At -2 °C, for example, the COP will vary between 4 and 1.5.

The different types of COP for a heat pump

Heating systems have several types of COP in the heat pump characteristics.

The commercial COP: is calculated as the ratio of the thermal energy produced to the electrical energy used by the heat pump based on an outdoor temperature of 7 °C for air-to-water heat pumps and 10 °C for water-to-water heat pumps.
The annual COP is the COP saved over an entire heating period. It corresponds to the average COP value of the heat pump. This indicator shows the actual efficiency of the heat pump.
The overall COP: This performance coefficient is calculated by taking into account the energy consumption of the heat pump during icing, the energy losses during heat distribution (in the house), and the energy consumption of additional equipment.
Seasonal COP: The heat pump’s seasonal coefficient of performance (SCOP) is calculated by considering the entire heating season, outdoor temperature changes, and changes in the climate.

These different COPs provide us with:

Information about the heat pump’s output.
The consumption of the additional equipment.
Possible energy losses.

cop vs ambient — COP vs Ambient temperatures

Before choosing an aerothermal or geothermal heat pump, it is advisable to find out the COP of the heat pump you are looking to purchase. It is usually indicated in the technical specifications of the device. To calculate the energy savings, it is also advisable to determine the price per kilowatt-hour.

You can find more by reading this document provided by the Australian government website https://www.energyrating.gov.au/sites/default/files/documents/200417-mepsheatpumps_0.pdf

FAQ

What is heat pump and its COP?

The COP of a heat pump is determined by the ratio of power output (in kW) to power input (also in kW).

What is a good COP for a heat pump?

The efficiency of a heat pump is often times determined by numerous task-specific factors, but in general terms, ground source heat pumps usually have a COP (coefficient of performance) that exceeds 4. On the other hand, air source heat pumps typically boast lower efficiencies–a COP above 3 would be considered good for this type of machine.

Is a higher or lower COP better?

The Coefficient of Performance (COP) measures the efficiency of a heating or cooling unit by dividing the amount of energy it provides by the amount it consumes. A higher COP means a more efficient system.