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Development of a highly efficient, innovative beverage COOLer

Final Report Summary - ICOOL (Development of a highly efficient, innovative beverage COOLer)

Executive Summary:

The total EU stock of beverage coolers is currently 6.3 million, which is nearly 50% of the total number of commercial display refrigerators in use. So far commercial refrigerators have remained outside EC legislation. However, this is likely to change as it is now generally accepted that commercial refrigerators offer significant potential for energy savings. A recent working document for the implementation of the Ecodesign Directive outlines several legislative options that will encourage and mandate significant energy efficiency improvements for beverage coolers. Compared to similar sized domestic refrigerators, the energy consumption of commercial beverage coolers can be over 3 times higher, even after allowing for increased heat loads, due to use of glass doors, for example.

With financial support from the European Commission under the FP7 programme, the iCOOL consortium has developed the world’s most efficient glass fronted beverage cooler. Compared to existing products, iCOOL technology enables energy consumption reductions of up to 80% with minimal impact on the conventional design of glass fronted beverage coolers. This step change in energy consumption has been achieved by a unique patent protected technology which makes effective use of a thermal buffer within the beverage cooler. This has enabled radical downsizing of the cooling system, enabling use of a high efficiency compressor.

The project has resulted in energy consumption of 1 kWh/day, which is better than expected. This means that iCOOL can deliver energy savings of 80% compared to the base case (2010) and 50% compared to the best beverage cooler available in the market during the project. This means that iCOOL can deliver lower emissions, reduced energy demand and associated cost for retail outlets.

Project Context and Objectives:
The iCOOL project set out to develop the world's most efficient glass fronted beverage cooler. The aim was to utilise an active thermal buffer using a phase change material (PCM) to enable radical downsizing of the cooling system, hence enabling energy savings of over 80% compared to state of the art. All this had to be achieved with minimal impact on the design and manufacturability of conventional glass fronted beverage coolers. The iCOOL consortium have managed to achieve this target delivering a beverage cooler with a daily energy consumption of 1kWh, with minimal impact on the design and cost. The now patented technology is based on an innovative use of a thermal buffer within the beverage cooler. This buffer enables a radical downsizing of the cooling system. This means that there is no need for an oversized cooling system, typical for commercial beverage coolers and until now necessary to achieve the required pull down cooling time targets. iCOOL does not affect the pull down time (time required to cool down warm drinks). Other associated improvements made during the project relate to insulation, lighting and other heat load factors.

Project Results:
Result 1: Models, experimental research results and reports
During the project the RTDs performed a range of preparatory research activities. These ranged from verification of the energy consumption of existing beverage coolers to a detailed study into the types of phase change materials that can be applied to these beverage coolers. The RTDs captured all their findings and prepared models that were subsequently used to validate iCOOL development. As iCOOL focused on a wide range of associated developments covering the introduction of a thermal buffer; reducing heat loads factors; and downsizing the cooler system. Due to the interrelationships between these factors it was important to develop a reliable model which enables the SMEs to decide which components/factors to adopt in commercial beverage coolers.

Result 2: Design and prototype evaporator and PCM shelves
Alongside the actual thermal buffer development, the RTDs focused on determining the most effective use and position. In the original concept it was believed that both shelve and wall integration would be most appropriate. During the project, once it had been determined that water/ice would be the most suitable thermal buffer media, simulations and practical experiments were performed to determine the best possible integration. As the efficiency of heat transfer is mainly a function of air flow, it was found that shelve integration was not suitable and would actually inhibit air flow. A special report was prepared and submitted with the Period 2 report.

Result 3: Design and prototype of evaporator and PCM walls
As per Project Result 2, during the R&D work it was established that the best possible integration of a thermal buffer was in its own 'air channel' within the back of a typical refrigerator cabinet. This enables a specific airflow pattern. The design of PCM encapsulation (buffer) was of aluminium with an integrated evaporator although it is likely that a plastic version will be more suited for commercial purposes.

Result 4: Control software and hardware prototypes
Three functional prototypes were prepared following the best possible and most efficient iCOOL version possible. Following a DOW change after Period 1 it was agreed to also allocate funding to development of a version with slightly higher daily energy consumption but which had a lower associated initial cost. The RTDs developed a bespoke control system in cooperation with the SME partners, writing firmware to control the cooling system as well as the valves controlling the buffer store operation. The main novelty is the use of two evaporators, one in the PCM/buffer store and one in the lower half of the beverage cooler. Operation depends on air temperature with the buffer being switched on when detecting a large temperature gradient. This minimising the load on the compressor during peak operation. An sensor provides information about the state of the phase change.

Result 5: Overall beverage cooler design and prototype including auxiliary systems
As outlined above, a beverage cooler was designed with integral buffer store. Other design factors included improved insulation (door and walls); application of highly efficient fans, compressors and auxiliary components. Four prototypes were produced and tested both in the lab and in the field. A bill of materials exists that will enable the SMEs to specify a production version.
Potential Impact:
The iCOOL project has resulted in a new modular technology platform for commercial beverage coolers. It enables energy consumption to be reduced by over 80% with minimal impact on the design of a typical glass fronted beverage cooler. The main enabling technology is a flexible PCM buffer store that can be intelligently controlled to provide extra cooling capacity when required. This has enabled radical downsizing of the cooling system, achieving major energy savings. As a result it is possible to use a R600a refrigerant instead of a R134a refrigerant which has major efficiency benefits as well as environmental benefits. R600a global warming potential (GWP) is just 3 compared to 1,300 for R134a. Achieving energy savings of over 80% will enable energy savings of up to 1,515kWh per annum per refrigerator, equivalent to a CO2 emission saving of 606kg/year. These are major savings for end users who could save over 300 euro per annum per refrigerator. iCOOL will therefore have a major impact on conserving energy, reducing emissions and reducing electricity bills for businesses.

The partners have prepared a project video, press release and conference articles which will all help to broadcast the project results to relevant target stakeholder groups. The SME partners have formed an exploitation vehicle, iCOOL Global Ltd, which will hold all project foreground including the patent application resulting from the project (already submitted). The SMEs will decide on how to proceed and whether to seek private investment or other type of funding to enable commercialisation. As an end user Heineken has been asked whether they are interested in purchasing iCOOL beverage coolers with a business case developed to demonstrate the benefits.

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