What is SCOP and how to read a heat pump datasheet
SCOP tells you how much heat a heat pump delivers for each kWh of electricity. How to read it and how much it really saves.
Whenever you compare heat pumps you come across the same acronym: SCOP. It is the figure that weighs most on running costs, and the one most often misread.
What it measures
SCOP (seasonal coefficient of performance) divides the heat a heat pump delivers over a heating season by the electricity it uses. A SCOP of 5 means that for every kWh of electricity the installation delivers 5 kWh of heat.
It is an average over the whole season, not an instantaneous value, and it is calculated under conditions set by the European standard. That makes it good for comparing machines with each other, but it is not exactly what your home will measure.
What it depends on
The water temperature your home asks for is the most important factor. The lower it is, the better the heat pump performs. Datasheets show it with two figures:
| Machine | SCOP with underfloor heating (35 °C) | SCOP with radiators (55 °C) |
|---|---|---|
| Geothermal Thermia Sigrin | 5.15 to 5.28 | 4.03 to 4.19 |
| Air-source Thermia Elve | 4.89 to 4.96 | 3.99 to 4.01 |
The figures are for an average climate and come from each machine’s datasheet. In a cold climate the gap grows: the geothermal Sigrin 13 reaches 5.48 and the air-source Elve L falls to 4.46, because the outdoor air is colder and the ground is not.
How much you save
Compared with a system that turns electricity directly into heat, such as an electric radiator, the electricity saved is 1 − 1/SCOP:
| SCOP | Electricity saved |
|---|---|
| 3.0 | 67 % |
| 4.0 | 75 % |
| 5.0 | 80 % |
| 5.9 | 83 % |
Compared with an oil or gas boiler you cannot use this formula, because the saving depends on the price of each energy. That needs a comparison of your bills, which is what the feasibility study does.
Three tips for reading a datasheet
- Check the temperature the SCOP is given at. A figure at 35 °C and another at 55 °C cannot be compared. Always ask which one applies to your heating system.
- Check the reference climate. Datasheets usually give values for an average climate. In a colder area the real result will differ.
- Do not stop at the machine. The final performance also depends on sizing, circuit design and control.
A practical point
Going from radiators at 55 °C to underfloor heating at 35 °C raises the SCOP of the geothermal Sigrin from 4.03–4.19 to 5.15–5.28, according to its datasheet. If you are renovating anyway, it is a good moment to consider it. There is more on the two technologies in geothermal and air-source.
Tell us about your project and we will tell you which system fits
The feasibility study is free and carries no obligation. We analyse the building, the ground and the heating and cooling needs.