Efficiency ratings

SCOP

Seasonal coefficient of performance, the European measure of heat-pump efficiency across a whole heating season and climate profile. It is the figure quoted on United Kingdom and European product labels and is more realistic than a single-point COP.

Also called seasonal COP

Direct answer

What is SCOP?

SCOP is the seasonal coefficient of performance: heat delivered across a whole heating season divided by the electricity used, measured against a defined European climate profile.

SCOP: how it works

The procedure runs the machine across the temperatures in a defined heating season, weights each by its share of that profile, and includes the electricity used by auxiliary heat and defrost. Because the outcome depends on the quoted climate profile and flow temperature, two SCOP figures are comparable only when both match.

Where you meet the term

  • On the energy label of any heat pump sold in the United Kingdom or the European Union.
  • In a grant or incentive scheme, where a minimum SCOP is part of eligibility.
  • In a comparison between models, where the flow temperature the SCOP was quoted at is the detail that decides whether it is a fair comparison.

How to check it

  1. Read the flow temperature the SCOP was quoted at. The same machine publishes a higher SCOP at 35 C than at 55 C. A figure without that context is not comparable. Owner check
  2. Check the climate profile used. Average, warmer, and colder profiles produce different numbers, and the label states which one applies. Owner check

Figures you will see

Published SCOP figures with the condition each one applies to. Confirm against the documentation for your own model before acting on any of them.
ConditionFigureWhat it tells you
Quoted at low flow temperatureHigher SCOPThe 35 C figure, suited to underfloor heating
Quoted at higher flow temperatureLower SCOPThe 55 C figure, suited to radiator systems
North American counterpartHSPF2Different test, different units, and not convertible
Read this twice

SCOP: what it is not

  • SCOP is not comparable with HSPF2. The seasons, the climate profiles, and the units all differ.
  • A SCOP figure without its flow temperature and climate profile is a marketing number rather than a comparison.

SCOP questions

What is a good SCOP?

It depends on the flow temperature quoted. A figure at 55 C is a harder test than the same machine at 35 C, so compare like for like and match the figure to the flow temperature your emitters will actually need.

Is SCOP what my heat pump will actually achieve?

It is a standardised comparison, not a prediction for your building. Installation quality, emitter sizing, controls, and how the system is run all move the figure you actually get.

Can I compare SCOP with the HSPF2 on an American unit?

No. HSPF2 is measured in BTU per watt-hour against United States climate assumptions, while SCOP is a dimensionless ratio against European profiles.

Where this definition comes from

Written from government guidance material held in the HVAC Bench evidence record. Where a document limits a definition to certain models, that limit is repeated here rather than generalised across a brand.

  • Energy label and ecodesignEuropean Commission · government guidanceThe European framework behind SCOP, seasonal space heating efficiency, and the product energy label.