Bitzer ammonia pack cuts frozen costs
1st February 2025
UK: A new Bitzer ammonia refrigeration system installed by Armstrong Refrigeration Services Ltd at a Lincolnshire-based frozen food specialist is reducing energy costs by more than £100,000 a year.
The ACP-85 ammonia compressor pack is providing up to 310kW of cooling to a large frozen food store for high quality fruit and vegetables at Greenyard Frozen UK’s site in Boston.
The inverter-driven pack replaces a refrigeration system that was nearing the end of its working life, and proving inefficient and costly to maintain.
Ben Armstrong, director of Armstrong Refrigeration Services Ltd, who headed the project, said: “The customer’s main requirements were to reduce energy consumption, cut servicing costs and provide the necessary cooling duty with a compact solution that could be accommodated in the plant room, given the space constraints.”
He added: “The existing pack was to be retained for use as a standby unit, and available space was limited.”
Commissioning specialists from Bitzer UK and Germany were on hand to provide technical support for the installation, the first ACP pack to be installed by Armstrong.
The project was planned to minimise cooling down-time, and the switchover from the existing plant to the new Bitzer ACP was completed in just half a day.

Since the ACP system was installed, energy use has fallen by 20%, delivering savings in running costs of more than £100,000 over a full year. When savings in servicing costs are added, pay-back on the project is anticipated to be comfortably less than one year.
Following the project’s success, a second Bitzer ACP system has been specified to replace another end-of-life pack at Greenyard’s Boston site.
In addition to its part-load efficiency and rapid commissioning due to its plug-and-play design, the ACP range also provides the security of a back-up compressor.
The VSD screw compressors significantly increase part-load efficiency and enable soft-start.
“Ammonia refrigeration systems have traditionally been built as one-offs, often in less than ideal conditions. Bitzer is able to build ACP units in a high quality factory environment, ensuring the highest possible system integrity, essential when working with ammonia,” commented Bitzer UK MD Kevin Glass.