Fridge-maker Thermo King has picked up a John Connell technology award from the Noise Abatement Society for its SLX low-noise fridge unit.
The SLX is the first diesel-powered chiller to meet the Dutch Piek standard for quiet operation, using extra insulation and a low-level exhaust to produce less than 60db.
Thermo King is also trialling an almost-silent 'cryogenic' fridge that uses liquid CO2 to cool the load space. Instead of a diesel-powered compressor, liquid CO2 held in an onboard tank is evaporated and vented into the air. The CO2 is captured from industrial processes and would have been vented to the atmosphere anyway, so no extra greenhouse gases are produced and the system is virtually carbon-neutral.
The drawbacks are, however, a significantly higher capital cost and the need for a liquid CO2 storage system to 
refill the vehicle tanks roughly every three days of operation.
The cryogenic system has received an enthusiastic reception from Continental retailers, including Spar and Dutch firm Royal Ahold, but after trials, supermarket Tesco has rejected the technology due to cost.
Accepting the award for the SLX at the House of Commons, Thermo King vice-president transport solutions, Johan van Maercke, said: "We hope legislation will encourage adoption of this and future technology, which will be even quieter."
Thermo King UK sales manager Steve Williams says a lack of agreement on noise limits and out-of-hours deliveries among central and local government was holding back investment in quiet technology by retailers. Sainsbury's recently halted development of a quiet vehicle after Doncaster Council refused to allow it to be used for out-of-hours urban deliveries.