ACR Journal

CMYK / .ai CMYK / .ai CMYK / .ai acrjournal.uk 17 REFRIGERATION to compare different refrigerants as shown in the subsequent graphs. Under relatively ‘ideal’ conditions for high and interim medium GWP refrigerants discounting heat recovery activities, the data in graph 1 demonstrates that R407F would offer a 3.3% reduction in lifetime emissions compared to R744. However, if more representative conditions are applied, including a 10% annual leakage rate, current carbon intensity figures from the National Grid, and load diversity factors, the carbon footprint changes significantly as shown in graph 2. R404A - 60 kWMT R407A - 60 kWMT R407F - 60 kWMT R744 - 60 kWMT Indirect 6,749,796 6,199,464 6,030,252 6,980,940 Recycle 141,192 72,000 65,664 720 Leakage 1,411,920 720,000 656,640 360 - 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000 6,000,000 7,000,000 8,000,000 9,000,000 kg CO2e Graph 1 Lifetime equivalent CO 2 emissions in ‘ideal’ conditions R404A - 60 kWMT R407A - 60 kWMT R407F - 60 kWMT R744 - 60 kWMT Indirect 2,150,232 1,946,664 1,947,024 2,320,092 Recycle 141,192 72,000 65,664 720 Leakage 2,823,840 1,440,000 1,313,280 720 - 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000 6,000,000 kg CO2e Graph 2 Lifetime equivalent CO 2 emissions in representative conditions. Considering all the different variables that retail refrigeration systems have to manage, R744 offers a significant reduction in carbon footprint and demonstrates a much lower relative impact through leakage compared to other refrigerants. Catastrophic loss of a refrigerant from a system is not always considered when comparing the direct impact refrigerants. Such losses have substantial impact to the environment, especially when involving high GWP refrigerants. A recent loss at a Scottish abattoir in Perth accounted for 87% of all HFCs released in Scotland during 2021 and potentially 0.87% of all of Scotland’s greenhouse gas emissions for 2021. Furthermore, as the national grid lowers carbon intensity further or additional local renewable energy generation is applied, the relative environmental gains from R744 will improve. 2020 Onwards: Closed Fronted Chilled Display Cabinets and other System Refinements In 2020 Aldi carried out a widespread trial of doored chilled display cabinets.