Clean cold technology company, Dearman, has released new information about the true extent of nitrogen oxide (NOx) emissions from diesel-powered transport refrigeration units, following a study into the matter.

Research conducted by the UK-based business proved that replacing the country’s fleet of diesel-powered transport refrigeration units with zero-emission alternatives could cut NOx emissions by 73% - the same as taking around 1.9 million diesel cars off the road. 

It discovered that poorly regulated auxiliary diesel engines, which are generally installed in refrigeration systems on trucks, can emit up to six times the NOx and 29 times the particulate matter of a truck’s Euro6 propulsion engine.

Additionally, a study released last year showed that pollutions from transport refrigeration could cost EU countries approximately €22bn ($24.7bn) over the next decade, with the EU refrigerated road vehicle fleet set to grow to almost 1.2 million by 2025.

In a bid to combat these rising emissions, Dearman’s transport refrigeration engine uses the rapid expansion of liquid nitrogen (N2) which is emits zero NOx and zero pollutants associated with combustion, unlike conventional systems.

Michael Ayres, Deputy CEO of Dearman, outlined, “There is a real opportunity to significantly reduce NOx emissions by addressing diesel engines that are all too often overlooked.”

Several cities throughout the UK, such as Birmingham, Leeds, Derby, Southampton and Nottingham, plan to introduce ‘clean air zones’ by 2020, in a bid to tackle rising air pollution. The scheme will see various polluting trucks and buses charged to enter certain zones within the city.

Impact of zero emission transport refrigeration system infographic

Dearman impact of zero emission transport refrigeration system infographic

Source: Dearman


Dearman’s research is based on equipping a Euro6-standard 17-tonne rigid body truck with a zero-emission refrigeration system as opposed to a diesel-powered unit.