COP and SCOP: heat pump efficiency | Riviera Home Experts

What do COP and SCOP measure?

COP (coefficient of performance) is how much heat a heat pump gives out for each unit of electricity it uses, measured at one moment under test conditions. A COP of 4 means 4 kWh of heat for every 1 kWh of electricity. SCOP (seasonal COP) is the same ratio averaged over a whole heating season. It's the figure that predicts your bills, so it's the one to compare between quotes.

Why does a heat pump's efficiency drop in cold weather?

The colder the outside air, the harder a heat pump has to work to pull heat out of it. That's why a data sheet lists several efficiency figures at different outdoor temperatures. On the coast, from Menton to Cannes, it rarely freezes, so a heat pump spends most of the winter in its efficient range. For a house inland or in the hills, ask the installer for the figure at the coldest temperature on the data sheet too.

Your radiators decide how well an air-to-water heat pump performs

An air-to-water heat pump heats the water that runs through your radiators or underfloor pipes. The cooler that water can run, the better the ratio. Underfloor heating works at a low water temperature and suits a heat pump well.

Older radiators were sized for a boiler running much hotter. A heat pump pushed to match that temperature loses a large part of its efficiency. Ask the installer what water temperature they designed the system around, and whether your existing radiators can heat each room at that temperature. If some need swapping for larger ones, that should be on the quote.

What SCOP should an air-to-water heat pump reach in southern France?

The SCOP printed on the EU energy label is calculated for an average European climate, which is colder than the Riviera. So a unit installed here usually does a little better over the season than its label says. For an air-to-water heat pump feeding underfloor heating or low-temperature radiators, a SCOP around 4 or higher is good. If a quote shows a SCOP below 3, ask why that unit was chosen and what water temperature the installer has assumed.

How much electricity does a higher SCOP save?

Electric radiators turn each kWh of electricity into one kWh of heat. For the same warmth, a heat pump uses only a fraction of that electricity, and the higher the SCOP, the smaller the fraction. The gap repeats on every bill for the life of the unit. Ask each installer to match the unit to your heating circuit before you compare prices.

SEER: the cooling figure on a reversible heat pump

A reversible heat pump or split air conditioner also carries a SEER figure. It's the same seasonal ratio, measured for cooling: a SEER of 5 means 5 kWh of cooling for each kWh of electricity. If you'll run the unit through the summer, compare both figures between quotes.

Which efficiency figures should a heat pump devis show?

Before you sign, ask for the devis (written quote) or the attached data sheet to show:

the SCOP for heating, and the SEER as well on a reversible unit
the energy label class
for air-to-water, the water temperature the system is designed to run at

Grants give you a second reason to check. CEE (energy-supplier grants) credits require the unit to meet an efficiency threshold, and so does MaPrimeRénov' (the state renovation grant) for an air-to-water heat pump in a principal residence. An air-to-air split is excluded from MaPrimeRénov' but can still earn CEE. Ask the installer to confirm in writing that the model qualifies for the grant they've quoted. If the quote names only a brand and model, ask for the manufacturer's data sheet.

COP and SCOP: heat pump efficiency ratings explained