More Efficient Heating & Cooling Technology Extends Electric Car Range

Vehicles powered by internal combustion engines use heat from the coolant to heat the passenger compartment. They also use the engine to run air conditioning compressors and power steering pumps. Since an electric car, by definition, has no engine to power things, they rely exclusively on the energy stored in their batteries for heating and cooling, and auxiliary systems like power steering and brake boosters. The more efficient those systems are, the longer the range of the vehicle.

Many electric cars rely on old fashioned resistance heaters to warm the passenger compartment — the same technology used for electric baseboard heat in buildings. It’s effective but uses a lot of electricity to get the job done. Other electric cars use heat pumps, which are more efficient but also cost more. Air conditioning still relies on a motor turning a rotary compressor.

The European Union has funding research into more efficient climate control systems by a consortium of researchers. The project is known as Horizon 2020 XERIC. The researchers announced this week the development of entirely new technology that heats and cools using less energy than conventional systems. One significant feature of their new system is that it separates the process into three components — heating, cooling, and humidity control. Each one of those components can then be engineered to do its job as efficiently as possible.

“We showed that the prototype can reduce by more than 50% the energy used for air heating, cooling and dehumidifying throughout the year compared to existing systems that rely on electric direct heating in wintertime. Furthermore, it can reduce by up to nearly 33% the energy used for air cooling and dehumidifying in extreme summer conditions,” says project coordinator Gaeta Soccorso.

Green Car Congress reports the researchers created a hybrid system that combines a liquid desiccant cycle to remove moisture from the air with a traditional compressor that cools the air. To extract humidity, the team created a highly compact three-fluid combined membrane contactor. That’s a bit of a mouthful, so it is abbreviated as 3F-CMC. The humidity in the air is captured by the membrane interface, which means little power from the battery is needed. On the compressor side of things, the team designed an electronic control system based on a variable frequency drive compressor and a brushless direct current motor that is up to 95 % efficient.

The XERIC system can be employed in any type of vehicles, including buses, trains, trucks, and boats. It can even be used in vehicles with internal combustion engines to provide climate controlled air for passengers more efficiently, thereby conserving fuel. The project might also lead to more efficient climate control systems for buildings. As the world warms, air conditioning is projected to consume more and more of the available electrical energy.

The team now has working prototypes available for potential customers to try and is exploring partnerships with original equipment manufacturers and tier one suppliers. Anything that helps extend the range of electric cars is welcome news as the EV revolution moves forward.