How Efficient Are Heat Pumps?

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By transferring heat rather than burning fuel, modern heat pumps can deliver three to four units of heat for every unit of electricity. Properly sized and installed systems achieve SEER ratings above 14 and HSPF ≥ 8.2, providing year-round comfort and significant energy savings.

What Exactly Is a Heat Pump?

Unlike furnaces that burn gas or boilers that resistively heat water, a heat pump uses refrigeration technology to move heat. In winter it extracts warmth from the outside air or the ground and releases it indoors; in summer it reverses the cycle to cool your home.

Because it moves heat instead of generating it, a heat pump can be up to 300%–450% efficient, delivering three to four units of heating or cooling for every unit of electricity consumed.

Types of Heat Pumps

• Air‑source (ASHP): The most common type; extracts heat from outdoor air. Cold-climate models can operate efficiently at temperatures as low as –6 °C (21 °F) and even –20 °C (–4 °F). Split or ductless systems are available.
• Ground‑source (Geothermal): Uses the stable temperature underground. These systems often achieve a higher Coefficient of Performance (COP) of approximately 4.5, compared to 3–3.5 for air-source units. They cost more to install, but maintain efficiency even during extreme cold.
• Water‑source: Similar to geothermal but draws heat from a nearby lake or aquifer. It provides steady performance but requires access to an appropriate water source.
• Hybrid systems: Pair an ASHP with a conventional furnace. The heat pump handles most heating needs, while the furnace serves as backup during very low temperatures.

Types of Heat Pumps Infographic by Scott Harding

Understanding Efficiency Ratings

Heat pump efficiency is expressed through several metrics.

• SEER (Seasonal Energy Efficiency Ratio) measures cooling efficiency over an entire season; 14 is the U.S. minimum, while high‑efficiency models achieve 18 SEER or higher.
• HSPF (Heating Seasonal Performance Factor) rates heating efficiency; the minimum is 8.2, while Energy Star models typically score 10–13.
• EER (Energy Efficiency Ratio) is used for geothermal systems and is calculated at a specific temperature; the Department of Energy calls 16.1 EER a minimum, but some systems exceed 30 EER.
• COP (Coefficient of Performance) shows how many units of heat a system delivers per unit of electricity—a COP of 4 means the heat pump is 400 % efficient.
• SCOP (Seasonal COP) averages COP over an entire heating season, accounting for variable outdoor temperatures. Higher numbers generally mean lower operating costs.

How Heat Pumps Compare to Conventional Heating

Modern condensing gas boilers operate at approximately 88–94% efficiency. Because heat pumps move heat rather than create it, they can deliver three to four times more heat for each unit of electricity.

This results in up to 75% lower heating costs and annual savings of around $550 for many households. Air-source heat pumps save approximately 65% of the electricity used for heating compared to electric resistance heaters.

Factors That Affect Efficiency

Even a high‑rated heat pump needs the right conditions to perform optimally. Climate matters—efficiency drops as the temperature difference between the heat source and your indoor space increases.

• Cold‑climate models maintain performance down to –6°C, and some operate at –20 °C. Correct sizing is crucial; undersized units run constantly, while oversized units cycle on and off.
• Insulation and air sealing help any heating system work more efficiently. Installation quality matters because improper refrigerant charge or ductwork can cut efficiency by 30 %.
• A clogged filter can reduce efficiency by 5–15%, so seasonal check‑ups and coil cleaning are important.

Finally, user behaviour counts: large temperature swings or frequent manual thermostat changes waste energy. Programmable or smart thermostats help maintain steady temperatures and can reduce heating costs by 10%.

How Heat Pumps Perform in Cold Climates

Early heat pumps struggled in freezing weather, but modern cold‑climate models have made tremendous advances. Today’s systems maintain a COP of about 2.44 (≈ 280 % efficient) at –6°C and can operate at temperatures as low as –23°F.

In extremely cold regions, hybrid systems combine a heat pump with a furnace to ensure comfort during rare cold snaps.

Geothermal vs Air‑Source Efficiency

Geothermal (ground‑source) heat pumps rely on the earth’s constant temperature. They achieve higher EER and COP values, often around 4.5, and maintain efficiency even at –40°C (–40°F), because the ground temperature remains between 5°C (41°F) and 15°C (59°F) year-round.

However, the installation requires trenches or boreholes, which increases the upfront cost. Air-source units are easier to install and have improved significantly thanks to variable-speed compressors and enhanced heat-exchanger designs. Both options offer substantial savings over gas or oil heating.

Maximising Your Heat‑Pump’s Efficiency

You can squeeze even more performance out of your system with a few simple strategies:

• Use a smart thermostat to adjust the temperature automatically when you’re asleep or away. Avoid turning the system off completely; maintaining a steady temperature is more efficient.
• Create zones. If you have a ductless mini‑split system, heat only the rooms you’re using. Zonal heating and cooling reduce energy consumption.
• Lower the flow temperature. Heat pumps tend to operate more efficiently at lower temperatures over longer periods. A flow temperature of 35–45 °C maximises efficiency.
• Pair with underfloor heating or oversized radiators. These systems work well at low water temperatures, increasing the heat pump’s COP.
• Schedule regular maintenance. Change filters, clean coils, and have a professional check refrigerant levels annually to prevent efficiency loss over time.

Costs, Incentives, and Payback

Air-source heat pumps cost between $4,000 and $12,000 (USD) installed, while geothermal systems range from $10,000 to $30,000. In Ontario, Canada, installation costs generally range from $3,000 to $15,000.

Many U.S. and Canadian provinces offer rebates or tax credits for high‑efficiency systems. For example, Canada’s Greener Homes Loan allows for up to $4,000 in energy-efficient upgrades, and the recently expired Greener Homes Grant provided rebates of up to $7,500.

In the U.S., the Federal Inflation Reduction Act provides a 30% tax credit for the installation costs of qualifying heat pumps. (Set to expire Sept 30 2025) Local utilities often offer additional incentives; check with your state or province for details.

Is a Heat Pump Right for Your Home?

Before switching, assess your home’s insulation, existing HVAC equipment, and climate. Heat pumps are ideal in moderate climates and well-insulated homes, but can also work in colder regions with appropriate sizing and a hybrid backup system.

If you rely on expensive fuel oil, propane, or electric baseboards, the payback period is shorter. Consult an HVAC professional to perform a load calculation and recommend the most suitable system for your specific needs.

Want to learn more about heat pumps? Explore more helpful guides right here on DIY Home Comfort.

Scott Harding

Scott is the main author of DIY Home Comfort. He's also an experienced HVAC technician that enjoys home renovation and spending time with his family. You can find out more about him here.