What are heat pumps and how do they work?

This article is brought to you thanks to the collaboration of The European Sting with the World Economic Forum.

Author: Simon Read, Senior Writer, Formative Content

• Heat pumps could help some consumers cut their soaring energy bills, although initial costs are high.
• They are an efficient way of controlling temperature in a building and there is evidence they cut emissions.
• Studies show the technology can help people living through record-breaking heatwaves.
• Heat pumps work on the same principle as a refrigerator.

As the energy crisis sends the cost of heating and air conditioning through the roof, you might be wondering if heat pumps are the answer.

They are pricey, but heat pumps promise to bring down energy bills and deliver savings in the end. And because they don’t emit carbon dioxide, they could also be better for the planet.

So how do they work?

There are two things to remember: first, no matter how cold it is outside – even if the temperature drops well below zero – there is always some thermal energy out there in the air or the ground. Heat pumps are designed to get enough of it into your home to warm you up.

Transferring heat into – and out of – the home

The second thing is, left to its own devices, heat always moves from a warmer place to a colder place – which is why houses get cold in winter. A heat pump takes control of that natural heat exchange process so you can either cool down or warm up your home.

It can do that because it contains a liquid refrigerant in a copper coil. This absorbs heat from the air outside, and then the pump uses electrical power to compress the refrigerant, increasing its temperature. That transfers the heat indoors.

The heat pump has reversed the natural flow of the heat and moved the energy available in a colder place (outside) to a warmer one (a house). It works on the same principle as a refrigerator.

In fact, US inventor Robert C. Webber came up with the idea in the 1940s when he accidentally burnt his hands on the outlet pipes of his deep freezer. Webber connected the pipes to a prototype heating system at his house, and the heat pump was born.

While air source heat pumps get their warmth from the earth, ground source systems draw it from the earth. They tend to be more expensive.

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How is the World Economic Forum fighting the climate crisis?

Our planet is straining under the burden of a global population of nearly 8 billion people.

The World Economic Forum’s Centre for Nature and Climate accelerates actions on climate change and environmental sustainability, food systems, the circular economy and value chains, and the future of international development.

• Through the Global Plastic Action Partnership, we are bringing together government, business and civil society to shape a more sustainable world through the eradication of plastic pollution.
• The centre is championing Nature-Based Solutions. Global companies are working together through the 1t.org initiative to support 1 trillion trees by 2030. Since September 2021, over 30 companies have committed to conserve, restore and grow more than 3.6 billion trees in over 60 countries.
• Through a partnership with the US Special Presidential Envoy for Climate John Kerry and over 30 global businesses, the Forum is encouraging companies to join the First Movers Coalition and invest in innovative green technologies so they are available for massive scale-up by 2030 to enable net-zero emissions by 2050 at the latest.
• The centre is also bringing leaders together to make commitments to a circular economy approach. Globally, the Scale360° initiative will reduce the environmental impact of value chains within the fashion, food, plastics and electronics industries – a significant step in making the $4.5 trillion circular economy opportunity a reality. The African Circular Economy Alliance is funding circular economy entrepreneurs and circular economy activities in countries including Rwanda, Nigeria and South Africa. In China, the Forum’s Circular Electronics in China project is helping companies reduce and recycle 50% of e-waste by 2025.
• The Forum is also crowdsourcing solutions to the climate crisis through its open innovation platform, UpLink. Since 2020 this digital space has welcomed over 40,000 users who are working on over 30 challenges including reducing plastic ocean pollution, scaling efforts to conserve, restore and grow 1 trillion trees and innovating the production and processing of aquatic foods.

Contact us for more information on how to get involved.

Efficient heating option

You could easily be looking at a bill of more than $10,000 to buy and install any sort of heat pump, so it is not a cheap option in the short term. But because they are designed to use less energy than the heat they generate, heat pumps should be an efficient way to heat your home.

Depending on the exact system, it will either heat the air indoors with fans, or be used to warm up radiators or underfloor heating.

If you want to use an air source heat pump to cool your home down in the summer, it simply goes into reverse. A heat pump in cooling mode should also lower the humidity in a house, which can make it a lot more comfortable.

Installed heat pump stock by region, 2010-2030. Image: IEA

Cooling homes and cutting emissions

There is a big demand for the technology in parts of the US where air conditioning is uncommon, but where people are now having to deal with more severe heatwaves because of climate change, Bloomberg reports.

One study from clean energy non-profit RMI modelled the performance of different cooling options in Seattle during a record-breaking heatwave in June 2021. Researchers found heat pumps were capable of cooling homes in extreme temperatures, and cost $228 less per year than having separate air conditioning and heating systems.

The same study said CO2 emissions were cut by around a quarter for the entire home.

The journey to net zero

The consumer journal Which? points out that because heat pumps use electric power, they are not zero carbon unless the electricity comes from renewable sources like solar or wind.

But they are being seen as part of the answer to the energy crisis and the journey to net zero.

Alexander Gard-Murray, a climate change researcher and economist at Brown University told the Washington Post: “It’s a home comfort issue. It’s a climate issue. It’s a security issue. Any one of them would be enough to move aggressively on heat pumps, but taken together I think the evidence is insurmountable.”