Heat-operated air conditioning for lorries will soon be a reality

An air-conditioning unit for lorries that is operated by heat rather than by electricity that is generated by the fuel that powers the vehicle's combustion engine. This is the goal of the development project that has now been granted funding by the Swedish Energy Agency.

The technique has been previously tested on a smaller scale with private cars, but in this project it will be further developed for use in lorries. The company Dometic – in cooperation with, among other companies, ClimateWell – will develop a heat-powered air conditioning system for lorries. The goal is to develop an air conditioning unit that is powered entirely by thermal energy from the lorry.

While the lorry is in operation it could prove to be a more efficient system than today's solutions. The idea is that the compressor should use heat rather than electricity that is generated from the combustion engine fuel in an inefficient way.

"The air conditioning systems in today's lorries are powered exclusively by mechanical compressors. This technology makes it possible to increase system efficiency," says Anders Lewald from the Swedish Energy Agency.

The low efficiency level is especially noticeable when the lorry engine is idling to provide comfort cooling in the cab during a break or when parking. This results in unnecessarily high fuel consumption and increased carbon dioxide emissions.

About the technology

ClimateWell has developed an absorption technique that converts thermal energy into cooling or more heat. The technique is at present used to convert solar energy into cooling inside buildings with the aid of solar collectors. What makes the technique especially suitable and interesting for lorries is that it does not contain any moving parts and that it is insensitive to vibrations.

The absorption module ClimateWell Unit (CWU) consists of a vacuum-sealed component containing only a salt solution and water vapour. No extra batteries or refrigerant are needed. The CWU then supplies cold refrigerant in the form of water to the AC unit Air Handler, which has been developed by Dometic.