Low-charge ammonia upgrade improves cold storage efficiency
19 June 2026
STAR REFRIGERATION has supplied and installed new plant for a refrigeration system upgrade at a Daventry distribution centre operated by DHL in partnership with J D Wetherspoon.
The project replaces an ageing pumped-circulation ammonia installation originally commissioned in 2004 with a modern low-charge system based on Star’s Azanefreezer platform. The new configuration focuses on a 290kW Azanefreezer 2.0 ammonia refrigeration system operating alongside an existing 120kW Azanefreezer 1.0 unit installed in 2016. Together, the systems serve a 31,000m³ frozen storage facility within a larger 192,000m³ distribution hub.
The upgraded design reduces the ammonia charge to approximately 220kg and removes the need for water consumption and associated treatment processes present in the previous system. Installation was carried out in phases during winter to allow the frozen store to remain operational throughout the transition and minimise disruption to distribution activity.
Operational performance is supported by the Star Ethos monitoring platform, which provides continuous system monitoring, performance analysis and predictive maintenance functionality. The installation has delivered measured reductions in electricity consumption and carbon emissions while improving overall refrigeration efficiency and operational visibility across the site.
