Improving cooling efficiency in the dairy aisle

The free resource was published by the IOR Environmental Committee and is a follow-up to a project that investigated the energy use and greenhouse gas emissions from the UK’s Transport, Industrial and Commercial Refrigeration (TICR) sectors.

It encompasses practical considerations associated with retrofitting doors and is based on, and published in line with, recommendations from the TICR project. In addition to a technology overview, the brief discusses applications, benefits, challenges, installation considerations, maintenance and training. Access a copy here.

For many Australian supermarkets, including Woolworths, Coles, Aldi and independents, the retrofitting of doors on refrigerated display cabinets including meat, dairy and deli items has become a key move in energy efficiency upgrade programs as refrigeration can account for around half a store’s energy consumption.

For example, between 2019–2021, Expert Group carried out a retrofit program for Ritchies IGA comprising 14 stores across Victoria, supported by the Victorian Energy Upgrade Program (VEU).

The package of works included retrofit of doors to display cases, replacing fluorescent lights with LEDs, upgrading the fans in the cold cases, and a controls upgrade to manage reduced refrigeration load.

Expert Group reported the outcomes were a 20.2% saving on total store electricity usage with an average payback on the investment of 18 months inclusive of the VEU rebate.

Overall, Expert Group says the benefits of having doors on refrigerated display cases include approximately 60% improvement in energy efficiency, improved customer comfort and extended product shelf life.

Another project, a pilot study carried out in New Zealand by Grant Robertson for Eco Systems found retrofit of doors to refrigerated dairy display cabinets “immediately and significantly” reduced energy consumption by 42%.

The report, Trial Retrofit of Doors on Open Refrigerated Display Cabinets, notes that energy efficiency gains are affected by the relative dew point of the local climate.

“While the energy savings shown in similar overseas studies have been between 25–30%, we believe the increased savings level at Countdown Pukekohe South can be attributed to the higher ambient dew point in Auckland when compared to the subject overseas climates,” the authors state.

“Investigating the strength of the relationship between the local climate and the refrigeration system in further simultaneous trials could be useful – e.g. in a warm humid climate (Auckland), a dry climate (Christchurch) and a climate with mid-range humidity (Palmerston North).”

The study also showed no lasting impact in terms of customer purchasing habits of products now located behind doors, and customers also reported an increased perception of comfort in the relevant aisles.

“The results of customer surveys taken in the month prior to and following the installation of the doors strongly supported doors on fridges with the number of customers in favour of doors on the dairy cabinets increasing from 53% in the pre-door survey to 99% following installation,” the report states.

Main image: Image by Alexa from Pixabay

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