Do heat pumps work in cold climates?

Yes, modern air source heat pumps work down to -25°C, though efficiency drops. In very cold climates (below -15°C regularly), ground source heat pumps are more efficient as ground temperature stays stable.

Can a heat pump replace my gas boiler?

Yes, in most cases. Heat pumps can provide all your heating and hot water. For maximum efficiency, you may need to upgrade radiators or add underfloor heating, and ensure good insulation.

How much electricity does a heat pump use?

A typical home needing 15,000 kWh of heat with a SCOP 3.5 heat pump uses about 4,300 kWh of electricity—roughly €1,300/year at €0.30/kWh.

Is a heat pump cheaper than gas?

Usually yes in Europe where gas prices are high. With SCOP 3.5 and electricity at €0.30/kWh, heat pump heating costs about €0.09 per kWh of heat—competitive with gas at €0.10/kWh even with 90% efficient boilers.

🌱Energy & Environment

Heat Pump Efficiency Guide: Understanding COP and SCOP

Heat pumps are revolutionizing home heating with efficiencies that seem impossible—delivering 3-5 units of heat for every unit of electricity used. This guide explains how heat pump efficiency works and helps you calculate potential savings.

4 min read

December 31, 2025

Updated: Jan 10, 2026

Modern heat pump unit installed outside a home for efficient heating

How Heat Pumps Achieve 300%+ Efficiency

Heat pumps do not create heat—they move it. Like a refrigerator in reverse, they extract heat from outside air, ground, or water and transfer it inside. Because they are moving heat rather than generating it, they can deliver 3-5 kWh of heat for every 1 kWh of electricity consumed.

Why >100% Efficiency Is Possible

Traditional heating converts fuel to heat at best 95% efficiency. Heat pumps MOVE heat, not create it: • 1 kWh electricity input • 2-4 kWh heat extracted from air/ground • 3-5 kWh total heat delivered This is not violating physics—it is just a different process!

What Is COP (Coefficient of Performance)?

COP measures instantaneous heat pump efficiency at specific conditions.

COP Formula

COP = Heat Output (kW) ÷ Electrical Input (kW) Example: 10 kW heat output ÷ 2.5 kW input = COP 4.0 This means 400% efficiency—4 kWh heat for every 1 kWh electricity!

COP to Efficiency Calculator

Convert COP rating to efficiency percentage:

Try the Calculator

Use our free Celsius to Fahrenheit converter for instant, accurate results.

🌡️Convert °C → °F

What Is SCOP (Seasonal COP)?

SCOP is more useful than COP because it represents average efficiency across an entire heating season, accounting for varying outdoor temperatures.

SCOP vs COP

COP: Efficiency at a single test condition (usually 7°C outdoor, 35°C output) SCOP: Average efficiency over entire heating season SCOP is typically 10-20% lower than peak COP because efficiency drops in colder weather. Always compare SCOP when shopping for heat pumps!

SCOP Savings Calculator

Calculate your savings compared to direct electric heating:

Modern heat pump unit next to residential home for sustainable heating

Heat Pump Types and Efficiency

Different heat pump types have different efficiency characteristics:

Heat Pump Type	Typical SCOP	Best For	Installation Cost
Air-to-air	2.5-3.5	Mild climates, single rooms	€2,000-5,000
Air-to-water	3.0-4.0	Most homes, radiators/underfloor	€8,000-15,000
Ground source	4.0-5.0	Cold climates, new builds	€15,000-25,000
Water source	4.0-5.5	Near lakes/rivers	€12,000-20,000

How Temperature Affects Efficiency

Heat pump efficiency drops as outdoor temperature falls:

Outdoor Temp	Air Source COP	Ground Source COP	Notes
15°C	5.0-6.0	5.0-5.5	Very efficient
7°C	4.0-4.5	4.5-5.0	Standard test condition
0°C	3.0-3.5	4.0-4.5	Ground source advantage
-7°C	2.0-2.8	3.8-4.2	Air source struggles
-15°C	1.5-2.2	3.5-4.0	Backup may be needed

Heat Pump vs Gas and Oil Heating Costs

Compare annual heating costs for a typical European home (15,000 kWh heat demand):

Heating System	Efficiency	Energy Needed	Cost/Unit	Annual Cost
Old gas boiler	75%	20,000 kWh gas	€0.10/kWh	€2,000
New gas boiler	92%	16,300 kWh gas	€0.10/kWh	€1,630
Oil boiler	85%	1,765 L oil	€1.00/L	€1,765
Electric heater	100%	15,000 kWh	€0.30/kWh	€4,500
Air source HP (SCOP 3.5)	350%	4,286 kWh	€0.30/kWh	€1,286
Ground source HP (SCOP 4.5)	450%	3,333 kWh	€0.30/kWh	€1,000

How to Size a Heat Pump

Proper sizing is critical for efficiency. An oversized pump cycles on/off too frequently; undersized cannot meet heating demand.

Basic Sizing Rule

Heat pump size (kW) = Home heat loss (kW) at design temperature Typical ranges: • Well-insulated new home: 3-6 kW • Average home: 6-10 kW • Older/larger home: 10-16 kW A professional heat loss calculation is essential!

Flow Temperature and Efficiency

Heat pumps are most efficient at low flow temperatures:

Maximize Efficiency

Lower flow temperature = Higher efficiency • Underfloor heating (35°C): SCOP 4.0-5.0 • Large radiators (45°C): SCOP 3.5-4.0 • Standard radiators (55°C): SCOP 3.0-3.5 • Old small radiators (65°C): SCOP 2.5-3.0 For best efficiency, upgrade to underfloor or larger radiators.

Heat Pump Payback Period

Calculate when your heat pump investment pays off:

Payback Calculation

Annual savings = Old heating cost - New heating cost Payback = (Installation cost - Grants) ÷ Annual savings Example: Old gas: €1,800/year Heat pump: €1,100/year Savings: €700/year Installation: €12,000 - €4,000 grant = €8,000 Payback: €8,000 ÷ €700 = 11.4 years

❓Frequently Asked Questions

SCOP 3.5+ is good for air source heat pumps, 4.0+ is excellent. Ground source heat pumps typically achieve 4.0-5.0. The EU energy label A+++ requires SCOP > 5.1.

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