green cooling initiative: Transport refrigeration

»Promoting green cooling worldwide«

Transport Refrigeration

Transport refrigeration is a vital part of every cold chain: Perishable goods, mainly food but also medical supplies and other goods, have to be refrigerated on their way from harvest or production to the consumer. Refrigerated transport increases food safety and prevents economic losses due to spoilage. Trucks and trailers are in many parts of the world the main mode of transport for refrigerated goods.

Different requirements for long-distance transport in trailers and distribution traffic in smaller vehicles leads to a range of cooling capacities from 4 to 20 kW. Similar to mobile ACs in passenger cars, the refrigerant leakage is high. These are in particular caused through constant vibrations during operation and at times when difficult road conditions lead to loose connections. Leakage rates can be as high as 20-30% per year.

Subsector Transport refrigeration
Typical application Trailers, large and small trucks but also containers and rail carriages are refrigerated in order to preserve perishable goods. Smaller units are connected to the motor directly or via an alternator. Bigger units have their own diesel units.
Typical end-users Retailers, logistic companies
Main refrigerants used HFC-134a, HFC-404a, HFC-410a
Short-term replacement R-452a
Charge size 1.5-7.5 kg average depending on cooling capacity
Natural refrigerant alternative HC-290, R-744 (CO2)
Cryogenic: liquid CO2 or N2
Growth rate / future demand Continuously growing market especially in emerging economies as importance of temperature-controlled transport is recognized widely

Scope of improvement: direct emissions 

  • Switch to natural hydrocarbon refrigerant HC-290 or HC-1270; several systems in development
  • Switch to natural refrigerant R-744; several systems in development
  • Leakage reduction (design/maintenance); e.g. use a hermetic compressor in alternator/inverter systems

Read more on the scope of improvement: direct emissions

Scope of improvement: energy efficiency 

  • Optimise components (e.g. compressor, heat exchanger)
  • Use inverter technology coupled with an alternator to improve part-load efficiency
  • Use HC refrigerant with favourable thermodynamic properties
  • Reduce leakage, as fully charged systems are more effective
  • Reduce cooling needs by improving the insulation of the vehicle, optimising delivery routes and proper handling of goods
  • Optimise dimension of refrigeration unit based on size, insulation and use of vehicle

Read more on the scope of improvement: energy efficiency