What do COP and SCOP mean?
4 min read below · SolarFast knowledge base
COP and SCOP tell you how much heat a heat pump delivers per kWh of power. The difference between the two figures and how to read them in a quote.
COP and SCOP show how much heat a heat pump delivers per kilowatt-hour of power. COP is a snapshot under fixed test conditions; SCOP is the average over a full heating season and therefore the fairest figure to calculate with. The higher, the more efficient.
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What is COP?
COP stands for Coefficient of Performance: the ratio between the heat a heat pump delivers and the power it uses to do so. A COP of 4 means one kilowatt-hour of power yields four kilowatt-hours of heat; the rest of the energy comes from the outdoor air or the ground.
Important to know: the COP is a snapshot at one fixed combination of outdoor temperature and supply temperature. Manufacturers measure it under test conditions so units can be compared fairly. On a cold winter day with hot radiators, the real efficiency is lower than that single brochure figure.
What is SCOP?
SCOP stands for Seasonal Coefficient of Performance: the same principle, but averaged over a full heating season, so including cold and mild days. The measurement method is fixed in a European test standard; the figure appears on the unit's energy label. Because the SCOP covers the whole season, it is the number to calculate with, not the peak COP.
What that delivers in practice: from one kilowatt-hour of power a heat pump makes three to five kilowatt-hours of heat, according to Milieu Centraal (Dutch). For comparison: an electric heater turns one kilowatt-hour of power into exactly one kilowatt-hour of heat.
From SCOP to power consumption
With the SCOP you can make a first estimate of power consumption yourself: divide your home's heat demand by the SCOP. If your house needs 12,000 kilowatt-hours of heat per year and the heat pump has a SCOP of 4, the estimate comes to about 3,000 kilowatt-hours of power.
That sum is deliberately rough: the real outcome depends on insulation, heat delivery system and heating habits. How to estimate your own home's heat demand and what it means for your energy bill is covered in detail in what a heat pump consumes.
What pushes efficiency down in practice?
The biggest lever is the supply temperature: the hotter the water to your radiators or floor has to be, the lower the efficiency. Milieu Centraal points this out explicitly for high-temperature heat pumps. Underfloor heating or generously sized low-temperature radiators keep the SCOP high; small old radiators push it down. That is why heat delivery and insulation belong in every heat pump quote.
How SolarFast uses these figures
During the site survey we do not calculate with the prettiest COP from the brochure, but with the SCOP that matches your supply temperature and heat demand. That prevents the expected consumption on paper being lower than what the meter shows later. Curious what that means for your home? See our heat pump page and request a quote.
Related articles
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A heat pump's power use depends on your heat demand and the SCOP. How to run the numbers yourself, and what pushes consumption up or down in practice.
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Without good insulation a heat pump works harder and costs more to run. How to test at 50 degrees and choose between hybrid or all-electric.
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Frequently asked questions
What is a good SCOP for a heat pump?
The higher, the more efficient. Modern air-to-water heat pumps typically reach a SCOP of around 4 with a suitable heat delivery system; with underfloor heating it is higher than with hot radiators. The figure appears on the unit's energy label.
What is the difference between COP and SCOP?
COP is a snapshot at one fixed test temperature; SCOP is the average over a full heating season. For a realistic estimate of your consumption, calculate with the SCOP.
Why does my heat pump not reach the brochure COP?
Because that COP is measured under ideal test conditions. On cold days and at high supply temperatures the real efficiency is lower. That is normal; that is why the seasonal SCOP is the fairer figure.
How do I calculate my power consumption with the SCOP?
Divide your home's annual heat demand (in kWh) by the SCOP. A home with a 12,000 kWh heat demand and a SCOP of 4 comes to about 3,000 kWh of power. It is a first estimate; insulation and heating habits determine the real outcome.
Is the SCOP on the energy label?
Yes, a heat pump's energy label is based on seasonal efficiency. The quote should state the SCOP matching your system's supply temperature; ask for it if it is missing.
We apply this every day
The same knowledge you're reading here, we put to work for households across the Netherlands.