Heat pumps: myths and benefits

From East Anglia Bylines

The first heat pump in the UK was installed in Norwich in 1945 by John Sumner, the city electrical engineer for Norwich. Nearly 80 years later the technology has made a resurgence: in 2024 there were a record number of heat pump installations in the UK. Over 60,000 air source heat pumps were installed last year alone. Yet despite this growth, only 1% of UK households currently use heat pumps.

This figure highlights a stark contrast between the UK and other European nations. The UK lags far behind in heat pump adoption, with just 412 heat pumps per 100,000 people compared to the European average of 3,068. This is largely due to our access in recent years to cheap coal, oil and gas.

The government’s ambitious target of 600,000 annual installations by 2028 remains a distant goal, hindered by high costs, limited awareness of how heat pumps work, and persistent myths about the technology putting people off making the switch.

A knowledge gap

While nearly half of UK homeowners express interest in low-carbon heating solutions, 73% admit they don’t feel informed enough to make the switch to heat pumps. To combat the knowledge gap, the government has invested £100,000 in a ‘nudge unit‘ to dispel myths and encourage adoption.

Heat pumps are still a relatively unfamiliar technology to many, leading to confusion about their various types and how they work. The three main categories—ground source, air source and water source – often leave people uncertain about which is most suitable for their homes.

Ground source heat pumps extract heat from the ground via buried pipes. This is the most expensive and is only cost-effective for large industrial buildings and apartment blocks.

Air source heat pumps, which are the most commonly used, capture heat from the outside air – even on cold days. There are two types: the more commonly installed “air to water” systems that provide heat to radiators or underfloor heating, and “air to air” systems circulating warm air directly into rooms via ducting.

Water source heat pumps draw warmth from a nearby water source, such as a lake or river, and are relatively rare.

Each type has its own benefits and drawbacks depending on where it’s being installed, but many people struggle to distinguish between them, particularly as air-to-air and air-to-water systems are sometimes grouped together under the same category. This lack of understanding can create confusion about the best system for individual needs, particularly as more people look to make sustainable choices for heating their homes.

Heat pumps can run at up to 400% efficiency, producing three to four times more energy than they consume. Homeowners can expect to save between £260 and £580 annually on energy bills by replacing an old gas or LPG boiler with a heat pump.

According to research by Confused.com Energy, public interest is evident. Searches for “are heat pumps worth it?” surged by 90% in recent months. However, high installation costs – averaging £10,000 for air source systems and £20,000 for ground source systems – remain a significant barrier. While prices are expected to drop by 20-25% by 2030, financial incentives like the UK government’s £7,500 Boiler Upgrade Scheme, and the Scottish government’s additional offer of a £7,500 interest free loan for residents in Scotland, aim to ease the transition now. Depending on the extent of the upgrade (some homes may need new radiators, or the owner chooses underfloor heating or adds solar and battery storage), in many cases, a simple installation may only take around 4.5 years to break even.

Addressing misinformation

A significant amount of misinformation – particularly online, but also from a certain section of the press – has contributed to scepticism about heat pumps.

Critics frequently claim that heat pumps are noisy. Modern heat pumps operate at noise levels comparable to a fridge, meeting strict UK guidelines that limit noise to 42 decibels at the nearest neighbouring property. In flats, compact air-to-air systems have proven successful options.

A common misconception is that heat pumps are ineffective in colder climates, yet they are widely used in Scandinavia where temperatures plummet far below those in the UK. Proper installation and sizing enable heat pumps to function efficiently even in uninsulated homes, as demonstrated in case studies ranging from stone churches to high-rise flats. Some types of heat pumps can work ‘in reverse’ to provide cooling in the summer.

As for insulation, while better-insulated homes allow heat pumps to work more efficiently, they are not a prerequisite. Properly designed systems can heat even uninsulated buildings to comfortable temperatures. Experts recommend improving insulation to maximise energy savings, with measures like loft insulation, double glazing, and adding draft excluders around windows and doors to reduce heat loss and improve overall system efficiency.

A recent survey by energy supplier Good Energy revealed that 15% of respondents mistakenly believed heat pumps require underfloor heating. In reality, heat pumps work effectively with radiators, although underfloor heating can enhance their efficiency due to its lower flow temperature. While some radiators may need upgrading, recent trends in radiator oversizing for safety margins mean existing ones may still suffice, depending on the property.

Economic and environmental benefits

The financial benefits of heat pumps are compelling. Homeowners can save between £260 and £580 annually on energy bills by replacing old gas or LPG boilers with heat pumps. Over time, these savings offset the upfront costs. Homeowners typically break even in 4.5 years. Beyond the financial appeal, heat pumps significantly reduce a home’s carbon footprint, cutting emissions by up to 90%. With home heating responsible for 18% of the UK’s emissions, widespread adoption could make a substantial contribution to achieving net-zero targets. There’s also evidence that installing a heat pump can increase property value by up to 3%. This boost in resale potential reflects growing demand for sustainable homes.

A flexible transition

The government’s push towards heat pumps is sometimes portrayed as coercive by naysayers, but there is no immediate mandate requiring homeowners to switch. Instead, policymakers aim to encourage adoption through incentives and education. Under the government’s Future Homes Standard proposal, gas boilers will be banned for new builds by 2027. While their policy is driving a shift towards low-carbon heating, homeowners in existing properties are free to transition at their own pace.

A proven technology

Heat pumps are not a new or untested technology – the concept behind them dates back to 1756 and was later used in refrigeration. Today, across the globe, nearly 200 million heat pumps are in operation, with proven success in diverse climates. Scandinavia’s widespread adoption demonstrates their reliability in extreme cold, while countries like Germany and France have shown how policy incentives can drive rapid adoption.

As the UK grapples with the twin challenges of high emissions and some of the highest energy costs in the world, heat pumps offer a viable solution. From their efficiency and long lifespan to their potential for cutting bills and boosting property values, the case for heat pumps is strong. But if the government wants to meet its target and gain widespread adoption, their ‘nudge unit’ is going to need to work hard addressing common myths, reducing upfront costs and improving public awareness.

The first step towards the use of heat pumps was taken in Norwich in 1945. Nearly 80 years later, it’s time for the UK to take the next.

We have what Australians call a "split reverse-cycle air-conditioner", which an "air-to-air" unit, heating in winter and cooling in summer.