Fruit and veg store energy costs cut by 25 per cent with RDM controls

RDM Intuitive controllerIntelligent controls from Resource Data Management are saving fruit and veg distributor Sharrocks 25 per cent in refrigeration running costs at its new fresh produce facility.

The cold store, at the company’s headquarters near Preston, is being cooled with a custom built, high efficiency refrigeration system equipped with the latest RDM control and monitoring systems.

The system was designed and installed by Leigh-based contractor Personal Refrigeration Ltd. Steve Bickett, who headed up the project for Personal Refrigeration, said: “Sharrocks imports produce from across the world. The company was relocating into new premises, and wanted an efficient new cold store to maintain product quality and maximise shelf life.

“With the rising cost of electricity, it was also important that the design minimised energy use in order to reduce running costs and protect the environment, while maintaining produce quality.”

Tight control of both temperature and humidity within the 28m by 13m cold room space was therefore essential. After calculating the heat load, based on anticipated flows of produce through the facility, Personal Refrigeration designed the refrigeration system with an overarching control solution based on RDM’s Intuitive The Data Builder (TDB), with touch screen interface and I/O expansion board.

The contractor designed the system to maintain a narrow Delta T of around 6K at all times, to maximise energy savings for the client. Key to delivering tight control was the use of control panels, custom-designed by the contractor, incorporating individual inverter drives for the plant’s two Frascold compressors.

The contractor supplied two “tropical” condensing units to accommodate the inverter-driven compressors. Control is managed by a custom-designed software programme, written by the contractor using the Intuitive TDB. This controls the inverters, which in turn modulate the frequency of power to the compressors, enabling control of pressure within approximately 0.2 Barg (+/- 0.5deg C) of evaporating set point.

This in turn also helps maintain high humidity in the storage area, to ensure quality is maintained. Humidity in the store is maintained above 85per cent most of the time, with more than 90per cent achieved during times of reduced throughput and product turnover.

The RDM system gives the end user and contractor access to real-time and historical data on the cold store via a web browser on a pc, tablet or smart phone, and offers almost infinite options to expand the system at a later date.

John Eastham, sales manager at Sharrocks, said: “Steve and the Personal Refrigeration team provided us with a flexible, accessible and efficient solution with professional support throughout the project. Their can-do approach and specialist knowledge, particularly in relation to refrigeration and intelligent controls, have been invaluable.”