Heat pumps do not generate heat, they move it.

Understanding heat pump efficiency: SCOP and COP.

When looking at heat pumps, you’ll often see the terms COP and SCOP. These are simply ways of measuring how efficiently your system turns electricity into heat.

COP — Coefficient of Performance.

Measures efficiency at one moment in time — usually in perfect test conditions.

For example, a COP of 4 means that for every 1 unit of electricity the heat pump uses, it provides 4 units of heat.
However, real life isn’t always perfect — temperatures change, systems switch on and off, and conditions vary throughout the year. That’s where SCOP comes in.

SCOP — Seasonal Coefficient of Performance.

Gives a more realistic picture of your heat pump’s efficiency over an entire heating season.

It takes into account:

• Changing outdoor temperatures as the weather warms and cools.
• Energy used during standby and defrost cycles.
• How efficiently the system runs at different power levels.

In short, SCOP tells you how efficient your heat pump is across the whole year, not just in ideal lab conditions.

How is SCOP Is calculated?

SCOP compares how much heat energy your system produces with how much electricity it uses:

SCOP = Total Heat Output ÷ Total Electricity Used

Example.

If your heat pump has a SCOP of 4, that means for every 1 kWh of electricity it uses, it provides 4 kWh of heat.

This is why it is often said a heat pump can be “400% efficient”, it’s not creating energy, just moving it very efficiently.

How the Heating Curve Aligns with COP and SCOP

One of the most overlooked settings on a heat pump is also one of the most important: the heating curve.

Get it right, and your home stays comfortable while your heat pump operates at peak efficiency. Get it wrong, and you could be using more electricity than necessary while reducing the overall performance of the system.

Understanding the relationship between the heating curve, COP and SCOP can help homeowners get the most from their heat pump.

Homeowners, optimising the heating curve can be one of the most effective ways to improve the performance of their heat pump without spending a penny on new equipment.