What are heat pumps in electric cars? Range-boosting feature explained

Heat pumps are becoming a common type of technology in the modern era, not only in homes and offices but in cars as well. Many electric cars are now offered with a heat pump, either as standard or as an optional extra.

Read on below to find out what a heat pump actually is, along with how it works and why you might want to spend the money and add one to your next electric car. They can be quite expensive, so you’ll want to know what’s great about them before making that decision.

What is a heat pump?

The quick version is that heat pumps are an efficient way to move heat around from where it’s not wanted to where it's needed. In an electric car, a heat pump is used to get the cabin up to temperature using heat from the battery pack. The car can also use the heat pump to keep the battery at an optimal temperature to improve charging performance, range and battery longevity - particularly in cold weather when lithium-ion batteries in electric cars perform less well.

How does a heat pump work?

Heat pumps use a compressor and a series of tubes full of refrigerant. The refrigerant is a substance that absorbs heat from the environment around it, turning from a liquid into a gas. As it cools, it condenses back into a liquid, releasing heat. 

We can control where this heat absorption and release happens so as the refrigerant moves through the heat pump’s tubes it brings heat from the battery into the car’s cabin. The cycle is the reverse of what happens in your fridge at home.

It’s the same principle as the air-conditioning in any car, although heat pumps are optimised for heating rather than cooling. In an electric car the system can also be reversed and this is used to bring warmth from the cabin to the battery when the car is charging, which improves battery life and capacity - EV batteries don’t like cold weather.

It takes some energy to run the compressor for the car’s heat pump, but it’s a lot less than would be needed to power a normal electric heater. Heat pumps do a lot to increase the efficiency of an electric car and keep the battery at an optimal temperature, so they are a very worthwhile addition to any electric car’s specification. 

Like air-con on petrol cars, we’re sure heat pumps will become a must-have addition to any EV in the years to come. Currently some electric cars have heat pumps fitted as standard but many still only offer them as a cost option for buyers. 

Why haven’t heat pumps been used on cars before? 

Heat pumps haven’t been popular until now because car engines already produce loads of excess heat in the combustion process, which is used to keep the cabin warm when needed. It’s only with electric cars where this tech can be used to its full potential.

Electric car batteries produce some heat, but it’s not enough to keep the cabin warm without a bit of help. EVs without a heat pump use a normal electric heater to keep the cabin warm, which isn’t very efficient.

Should I add a heat pump as an optional extra?

Most expensive electric cars including Teslas and Porsches come with heat pumps as standard, but many more mainstream EVs such as the Volkswagen ID.3, Skoda Enyaq and Hyundai Ioniq 5 don’t have them unless you pay around £1,000 to add one as an option. There are some more affordable models with heat pumps as standard: the BMW i4, Polestar 2, Tesla Model 3 and Peugeot E-208 all have them.

Not only do heat pumps work more efficiently than normal electric heaters, but they also keep the battery in better condition than a car without. For that reason, we’d recommend a heat pump as an optional extra over virtually anything else you can add to your new EV. You can expect about 10 per cent more range in your EV when it’s fitted with a heat pump, which is pretty significant and well worth the money.

Heat pumps are also great for getting the cabin to a comfortable temperature before you even set foot into the car (called pre-conditioning). This is usually done through the car’s app which lets you set the time you want to begin your journey and the temperature you’d like the cabin to be at that point. In the winter, this process will clear any ice from the car’s windows, too. Heat pumps are also desirable on second-hand cars so will improve resale value when you come to sell the car, too.

If you live somewhere with mild to warm temperatures all year round then a heat pump might not offer a huge benefit, but to virtually anyone in the UK and colder countries, a heat pump should be a top priority when choosing optional extras on an electric car.

Need to top up? Read our guide to electric car charging in the UK...

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