CoP, or coefficient of performance, is just one way in which heat pumps are measured in terms of energy efficiency. It takes into account energy consumption vs energy production, so you get a full picture of just how efficient your heat pumps are. CoP is provided for both air source heat pumps and ground source heat pumps.

Essentially, CoP looks at the heating system in the moment, and considers how much energy you’ve had to put into the heat pump to make it work, and then looks at the energy output to see how much you get out of the heat pump compared to what you’ve put in.

Since things can start to get complicated here, heat pump manufacturers provide a much simpler way for you to understand how the CoP changes throughout the heating season, by providing another figure: the seasonal performance factor (SPF).

Essentially it will consider the total electrical energy consumed throughout the year vs the total heat output to understand the coefficient of performance on average throughout the heating season.

The same applies to air conditioning. If it’s 25 degrees celsius outside, but you want to cool your home to 15 degrees, then again, your heat pump will require more electrical energy to reach the desired temperature compared if it was only 20 degrees out.

Heat pumps do not create new energy. Instead, they use the electric energy put into the heating system AND heat already present in the air or ground. An air source heat pump draws heat from the outside air, and a ground source heat pump draws heat from the ground.

Your heat pump’s efficiency can be measured in two main ways: coefficient of performance (CoP) and seasonal performance factor (SPF). Both are excellent ways to simply tell how efficient a heat pump model is, but it can be confusing if you’re unsure what both stand for. It can also be confusing to see two different figures for both measures.

If the SPF is shown as 3, then it means, on average throughout the year, your heat pump will produce 3 times more heat energy than electrical energy put in. However, at certain times of the year this could be as low as 0.5 or lower, or as high as 6 or more.

One of the main factors affecting your heat pump CoP is the temperature outside. During any heating season temperatures will fluctuate, meaning your heat pump will need to work more or less, depending on the air conditioning or space heating temperatures required vs the outside temperature.

A good illustration of how CoPs can change throughout the year can actually be seen with a solar thermal system, which is notoriously inefficient in colder climates, but can reach a CoP of over 70 when it’s sunny out.

SPF, or seasonal performance factor, is another way of measuring heat efficiency for heat pumps, but it factors in how a heat pump performs during different seasons, and then provides an average score, so you know, on average, how efficient your heat pumps are throughout the year.

In the example above, where 1kW of energy is provided by electrical energy, and 3kW of heat output is recorded, 2kW of heat energy must be drawn from another heat source (in these cases, the air temperature or ground temperature).

Understanding both the heat pump coefficient of performance (CoP) and seasonal performance factor (SPF) is key to understanding just how efficient heat pumps available on the market are. If you’re researching heat pump models yourself, then knowing these two figures and what they mean will be key.

CoP is expressed as a single figure, and it essentially tells you how much more energy you get out of your heat pump compared to what you’ve put in – where electrical energy is what you’ve put in, and heat energy is what you get out. For example:

Even if you aren’t familiar with the laws of thermodynamics, it stands to reason that if 1kW of energy is put in, 1kW of energy should be put out. The first law of thermodynamics says that energy can’t be created or destroyed, so how is it possible for a heat pump to produce more energy than is put in? Well, that’s the genius of heat pump technology.

The input temperature from the ground or air is then heated further using the 1kW of electrical energy, changing the output temperature and providing effective water or space heating for your home.

Below we’ll talk about how air source heat pumps and ground source heat pumps can be measured in terms of energy efficiency, explain what CoP and SPF scores are, and explore the differences between the two.

However, if you don’t have the time to research different models yourself, then you should rely on heat pump installers who are more familiar with the different efficiency measures to help you make the right choice.Work with Heat Pumps UK to find installers in your area offering the best deals on the most efficient heat pumps.

For example, if your heat pump was trying to warm your home to 17 degrees celsius, but the outside temperature was 0, then it would have to work a lot harder than if the outside temperature was 12 degrees celsius to get the output temperature desired.

Yes, they absolutely will. It’s quite complicated because it involves considering the primary energy factor (a measure of end user electricity consumed vs primary energy consumption), the temperature of the ground or air, and the amount of electrical energy required to power the heat pump (including where this energy is sourced from).