Energy efficient supermarkets - Cooling technology

Energy measurements and energy survey were performed in a Max Hamburger restaurant and nine energy saving measures were proposed. The greatest energy savings are heat recovery of the ventilation air, which is estimated to reduce the total district heating demand by about two thirds. An energy saving of just over 10 % can be obtained by minimizing the operating times of the grills. If all nine measures are implemented, the savings will be about 20 % of the electricity and just under 90 % of the district heating, or 42 % of the total purchased energy.

A theoretical model was used to investigate some alternative refrigerants for R404A in a freezer application in a grocery store, and the results indicate that energy consumption will be better with all the options.

A document which compiles the rules applicable to safe handling of flammable refrigerants and which can be approved as a guideline by the Swedish authorities, and to encourage the development of efficient energy use in food premises and thus contribute to national energy and environmental objectives has been produced. The document has been used in the development of Swedish Refrigeration norm for units with flammable refrigerants.

The report describes a demonstration regarding how the energy use in an existing supermarket can be reduced by recycling the heat released from one of the supermarket's refrigeration system. During the measurement period, the amount of purchased district heating was lowered by about 50% compared to the same period last year. The COP of the heat pump was around 4.

To take advantage of the energy reduction potential that retrofitting doors on refrigerated counters entails, other energy efficiency measures were implemented in the refrigeration system in a grocery store. After the measures, the cooling demand of the milk room decreased by as much as 60 % and the demand of the entire cooling system decreased by 50 %.

Dirt and dust are drawn into cooling batteries during operation and sometimes food packages break so that the content drips down into the counter. Contamination can cause decreased efficiency in the counter’s cooling coil, reduced air flow and clogging of drains, which can lead to an increased energy demand for cooling the air in the counter and to ruined food due to inadequate cooling. A checklist for washing cooling batteries has been produced.

In this pre-study we aim to shed the light and different perspectives for actors on how to achieve increased energy efficiency between tenant and landlord by energy contracts or energy agreement. This may lead to increased energy efficiency, better use of energy and reduce environmental impact.

The purpose of this pilot study is to investigate three different system solutions for food refrigeration and how they should best be designed to achieve the highest possible energy efficiency with a focus on the technical potential. The results show that dimensioning components, and the possibilities for regulation in a large work area, have a greater effect on energy performance than the choice between the three optimized cooling systems examined. It is important to dimension the components optimally for the operating conditions that are most common, in terms of hours/year.  

This prestudy which was completed in February 2018, specifies how a future implementation project will be set up in terms of technical solution (measurment and application/ interface) as well as testing and evaluation. 

This report presents possible alternatives for phasing out R404A, as R404A will have a sales ban in 2019 and a service ban 2020 - the most common refrigerant in stores, commercial kitchens and small food industries today. 

The aim of the feasibility study has been to produce a prioritized compilation of the most important measures for energy efficiency in food premises. The results show that energy efficiency does not have to be expensive - much can be done quickly and at a low cost. Usually no major investment is required in components or equipment.

To bring down the overall cost of energy is an important issue for all food stores. The most important thing is to work to reduce energy consumption through different types of efficiencies. In this study we have looked at various options for self-produced energy and calculated their profitability. The results show that it is profitable for large supermarkets to produce their own electricity. If electricity prices rise and / or installation costs drop improvement potential rapidly, even at moderate changes.

The purpose of this study is to compare and define new plug-in solutions for in-store cold with central cooling. The decommissioning of refrigerant such as R404A are a driving force to look at plug-in solutions. There is a risk that the phasing out of R404A will result in investment in coolers with inferior energy performance. Here, the work with eco-design requirements and energy labeling has an important role to play.

The purpose of the project has been to compile knowledge on how an existing grocery store can be renovated to reduce its energy use so that it approaches zero. Proposals for energy efficiency measures were developed in the categories of refidgeration, ventilation, heating and lighting. If all proposals were implemented, the theoretical savings potential was 60-65 percent.

Dehumidification of air in supermarkets has been identified as one way to reduce the energy use in supermarkets. The result shows that many larger supermarkets in Sweden include comfort cooling in their ventilation systems. This, in combination with that more display cabinets are equipped with doors and the use of ventilation with recirculated air contributes to that dehumidification of air is not considered to be a problem.

In this study, a new innovative type of air-to-liquid heat exchanger has been tested and demonstrated in an open display cabinet at a supermarket. The results from this study show that there is a potential of energy savings by using the new type of heat exchanger in display cabinets at supermarkets instead of conventional cooling coils.

Energy for refrigerators and freezers account for a significant proportion of grocery stores total energy use. This prestudy shows, among other things, that the conditions differ, depending on the size of the store. Large grocery stores often have the air supply temperature chilled during summer while there is no air conditioning at all in the smaller stores. This means that several operating conditions should be investigated. 

RISE has evaluated an innovative heat exchanger in refrigerated counters for more efficient energy use in stores. The evaluation shows that there are great savings potentials by replacing the existing conventional cooling batteries in the stores' refrigerated counters with this new type of heat exchanger.

The purpose of the project was to carry out a demonstration plant to make energy efficient an existing grocery store in two parts. The first part was to carry out a number of different energy-efficient measures in one of the store's cooling systems, to reduce the need for cooling and the need for purchased electricity to power the system. The second part was to make the store more energy efficient by recovering the heat that is released from the rebuilt cooling system for heating the premises and domestic hot water.

Doors on refrigerated counters and smart use of waste heat have reduced energy consumption in Ica City Knalleland by almost 80 percent. Soon, district heating can be completely turned off in the system, which is transferable to most stores.

The task within this BeLivs project is to demonstrate how the energy use in an existing grocery store can be reduced by putting doors on existing refrigerated counters. The store included in the demonstration has been carefully measured both before and after the measures taken to get real facts about how much energy has actually been saved. The initial estimate of a reduction in energy demand by about 30% would prove to be superior in reality.

The need to clean refrigerator and freezer furniture has been the subject of a BeLivs study, which focused on the profitability of washing the dishes' batteries. Direct and indirect benefits have been analyzed together with service companies and store owners.

RISE Research Institutes of Sweden has investigated how three different system solutions for food cooling should be designed to achieve the highest possible energy efficiency with a focus on technical potential. These have been defined as "Best Available Technology" (BAT). The goal is for increased knowledge of the system to lead to increased energy performance in the cooling system of the future.

With available refrigeration technology, we have been able to create a trade in fresh produce that has not been possible before. But it places high demands on our resources, globally 17% of all electricity is used for the refrigeration sector, which also includes air conditioning. The question is, how can we make energy efficient, with the consumer in focus?

This thesis is multidisciplinary, and the research has been broadened from studying measured and perceived comfort parameters in supermarkets to incorporating qualitative studies with a clearer and deeper interest in consumers’ perceptions and behaviors. In this thesis, findings from the cold environment of chilled food display cabinets, either with doors or without, are discussed and tangible commodities are used to illustrate how ‘details’ such as doors on cabinets matter to consumers. The consumers are of the main interest since they make up the businesses. The aim of this thesis is to gain knowledge of how to improve energy efficiency and the store layout for chilled groceries by adding consumer insights. Four specific
papers contribute to this thesis’ aim of overcoming specific challenges faced by retail grocery stores as regards energy efficiency.

Energy measurements and energy mapping were performed in restaurants and kitchens at IKEA and six energy-saving measures were proposed. The greatest energy savings are given to a rebuild of the cooling system that can reduce electricity consumption by 40 MWh / year or 6% of the kitchen's total electricity consumption. If all analyzed measures are implemented, the restaurant is estimated to be able to save 14% of the electricity for the kitchen and restaurant.