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Energy & Sustainability

Heat Pump Calculators & Efficiency Guides

Understand COP, SCOP and running cost — and see when a heat pump beats gas, oil or direct electric heating.

A heat pump moves heat rather than generating it, and that is why it can deliver three to five kilowatt-hours of warmth for every one kilowatt-hour of electricity consumed. The single number that describes this multiplier is the coefficient of performance (COP) — instantaneous — or its seasonal equivalent (SCOP). Getting these two right is the difference between real savings and a disappointing bill.

This hub explains COP and SCOP in plain terms, shows how outdoor temperature and flow temperature affect them, and walks through the arithmetic that decides whether a heat pump beats gas or oil in your climate and at your electricity price. The guides link out to supporting converters (temperature scales, energy units) whenever the math needs them.

Heat pumps also unlock deeper efficiency gains when paired with solar, battery storage or smart tariffs — running the compressor when electricity is cheap or clean. See the related pillars once you understand the core efficiency numbers.

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Heat Pump Savings Calculator

Compare annual running cost, payback and CO₂ reduction versus your current gas, oil, LPG or electric heating.

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Guides in this hub

In-depth articles covering the math, the assumptions, and the practical decisions for heat pumps.

Modern heat pump unit installed outside a home for efficient heating
🌱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.

Smart thermostat displaying energy savings on modern home wall
🌱Energy & Environment

Smart Home Energy Savings: Complete Guide to Reducing Your Bills

Smart home technology offers unprecedented control over your energy usage. From learning thermostats that optimize heating schedules to real-time monitors that reveal energy vampires, these devices typically save 10-30% on energy bills while improving comfort. This guide covers the best smart energy devices and strategies.

Electric power lines against blue sky representing CO2 emissions from electricity
🌱Energy & Environment

How to Calculate CO₂ Emissions from Electricity

Understanding how much CO₂ your electricity use produces is essential for reducing your carbon footprint. However, the answer varies dramatically depending on where you live and how your electricity is generated. This guide explains how to calculate your electricity emissions.

Supporting converters

General-purpose unit converters you will use alongside the guides above — area for panel sizing, temperature for heat pumps, distance for EV range.

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°C → °F

Celsius to Fahrenheit

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°F → °C

Fahrenheit to Celsius

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°C → K

Celsius to Kelvin

Dedicated calculators — in development

Purpose-built calculators for this pillar are being built. Until they ship, the guides above walk through the same math step by step.

Coming soon

COP / SCOP Calculator

Convert manufacturer data sheets into a realistic seasonal efficiency for your climate.

Coming soon

Heat Pump Sizing

Estimate required kW output from home size, insulation level and design temperature.

Frequently asked questions

What is a good SCOP for a heat pump?
For a modern air-source heat pump on a low-temperature (35–40 °C flow) heating system, a SCOP of 3.8–4.5 is achievable in temperate climates. Ground-source systems typically reach 4.0–5.0. High-temperature retrofit installations feeding radiators at 55 °C typically see 2.8–3.4 — still better than direct electric heating, but far behind properly designed low-temperature systems.
Will a heat pump save me money compared to gas?
It depends on the ratio between your electricity and gas price and on the heat pump’s SCOP. Roughly: if (electricity price ÷ gas price) is less than SCOP × 0.9 (accounting for gas boiler efficiency of about 90%), the heat pump wins. In most of Europe today this is true for well-designed systems, but the margin narrows when electricity is expensive relative to gas.
Do heat pumps work in cold climates?
Yes. Modern cold-climate air-source models retain 70–80% of rated capacity down to −15 °C and continue running to −25 °C, though at reduced efficiency. Ground-source systems are largely temperature-independent because ground temperature stays stable year-round at 8–12 °C below 1.5 m depth.
What size heat pump do I need?
For a well-insulated home, a rough rule is 30–50 W per m² of floor area at design outdoor temperature. A 100 m² house needs a 3–5 kW unit. Poorly insulated homes may need 60–100 W per m². A proper heat-loss calculation from an installer is essential — oversizing wastes money and causes short-cycling.
What is the difference between COP and SCOP?
COP (coefficient of performance) is measured at a single operating point, typically warm outdoor temperature. SCOP (seasonal COP) averages efficiency across a full heating season in a defined climate. SCOP is much more useful for real-world savings estimates because it reflects the reduced efficiency at cold outdoor temperatures.
Are heat pumps noisy?
Modern units produce 40–55 dB(A) at 1 m — comparable to a quiet fridge. Placement matters: mount the outdoor unit away from bedrooms and consider anti-vibration mounts. Ground-source systems have no outdoor unit and are essentially silent.

Explore related topics

Energy decisions rarely stand alone — solar pairs with batteries and EVs, heat pumps pair with insulation and tariffs.

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Electric Vehicles

Charging cost, range and total-cost-of-ownership math — from home charger sizing to petrol comparison.

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Home Energy

Understand your electricity bill, size home storage, and cut standby consumption — the everyday side of the energy transition.

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Carbon Footprint

Translate kilowatt-hours, kilometres, kilograms and litres into CO₂ — with emission factors you can verify.