Data loggers are used throughout the cold chain, in refrigerated vehicles and in food storage warehouses, to ensure compliance with industry-wide environmental, health and safety regulations including HACCP measures.

The whole of the frozen food supply chain in the UK could benefit from the results of a practical research initiative carried out by the British Frozen Food Federation (BFFF) using Tinytag temperature data loggers, saving thousands of pounds in its annual energy bill and reducing CO₂ emissions in the process. Furthermore the report will help companies in the frozen food industry to better understand the importance of using data loggers to improve temperature management and consequently the energy efficiency in their cold chain while complying with regulations.

It is estimated that between 10 and 20% could be saved on a site's annual energy bill by improving temperature management and consequently the energy efficiency of the cold chain. With an average site energy bill of over £0.5 million, such a saving becomes very significant.

The investigation was carried out in two periods, August 2008 and October 2008, to account for seasonal temperature influences, with the report results compiled early the following year. It researched the storage temperatures used by a representative group of companies in the frozen food industry (including poultry, seafood, ready meals, pizzas, vegetables, Yorkshire pudding and ice cream), in order to identify opportunities for energy savings and CO₂ emission reductions. As part of their Environmental Support Program, Gemini Data Loggers donated 64 of their Tinytag Transit data loggers, which meet European Standards BS EN 12830, and monitored temperature at various stages in the supply chain. From a sample of 8 food manufacturers and 5 logistic service providers, energy savings to the equivalent of 4,800 tonnes of CO₂ per annum were identified. The report goes on to suggest the scale of savings if the exercise was repeated across the whole of the UK frozen food supply chain.

Eight clear areas for improvement were identified and the data loggers proved invaluable in five of those areas. Some of these were:

• Raising cold store air temperature when a cold store was running at an unnecessarily low temperature
• Reducing the temperature difference between air and refrigerant
• Making a seasonal adjustment of evaporating temperature
• Avoiding air temperature fluctuations by establishing steady temperature control at the warmest temperature possible and avoiding over-cooling in blast freezers.

Most supply chain companies would be able to carry out at least some of the measures suggested, in order to make energy savings. While some measures require some capital investment (easily offset by saving on the energy bill), particularly in older premises, other measures such as raising the temperature in cold stores that are run unnecessarily low can reap significantly higher energy savings.

Key to the success of the project of identifying energy saving opportunities was to record representative temperatures of products moving through the supply chain. This was done by placing small Tinytag Transit temperature data loggers in boxes of frozen food stacked on pallets.

Food manufacturers and logistics companies in the frozen foods industry could replicate this exercise to see if their storage facilities and processes are operating at the correct temperature and are energy efficient. Temperature data collection and analysis using data loggers could assist in identifying specific energy saving opportunities and take quick corrective actions when required.

Another interesting finding identified in this report is the lack of energy sub-metering to monitor and improve performance. This clearly represented a missed opportunity to achieve energy savings. Data loggers, as a solution, could also be used to monitor power consumption.