Energy efficient supermarkets - Cooling technology
Food refrigeration demands a chain of refrigeration, from production to distribution, delivery and storage. From a hygienic perspective, it’s very important to maintain the right temperature level for the food throughout the cold chain, from production to consumption.
For supermarkets (shops and professional kitchens), there are two types of cooling systems, direct and indirect, both of which are energy efficient. Direct systems mean long pipes and thus larger amount of refrigerant but minimize the need of heat exchange. In indirect systems, only the pipes of the cooling unit are filled with refrigerant, which gives a much less amount of refrigerant filling. Indirect systems are a central cooling system that cools the secondary system with refrigerants that distribute the cooling effect to refrigerated furniture and chilled rooms.
When designing systems for cooling food, it is important to look at system efficiency in order to achieve low energy consumption over the year. More and more components included in the cooling system are covered by the Ecodesign Directive, which aims to make the individual components more energy efficient. An incorrectly designed system can provide an inefficient system solution, despite the use of energy-efficient components.
Heat recovery is often an energy efficient solution, but one should be observant that electricity use is increasing. The simplest way is to raise the condenser pressure in the heat exchanger high enough to be able to directly exchange the heat to the receiving heating system. Another alternative is to utilize low temperature heat from the cooling machines condensers and let a heat pump raise the temperature to a usable temperature.
Energy efficiency potential in professional kitchens - Fast Food Restaurant
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.
Evaluation of alternatives to R404A – the most common refrigerant in Swedish grocery stores
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.
Flammable Refrigerants – A survey of barriers and how to overcome them
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.
Heat recovery in refrigeration system by applying heat pump
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.
Doors on open display cabinets and modification of the refrigeration system in a supermarket
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 %.
Cleaning of heat exchangers in display cabinets
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.
Energy from tenant’s refrigeration system utilized in property owners heating system - a contribution towards increased energy efficiency
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.
Design of Refrigeration Systems for Supermarkets based on Best Available Technology
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.
Improved energy behavior in commercial kitchens through digital support with measurement and feedback
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.
Alternative to R404A
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.
Alternativ till R 404A (only in Swedish) (860.16 KB)
Priority actions in existing food premises for increased energy efficiency
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.
Profitability potential for self-produced energy in grocery stores
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.
Plug-in compared with central cooling unit
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 concept supermarket approaching zero
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.
Read more about: The concept supermarket approaching zero (only in Swedish)
Dehumidification of air in supermarkets
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.
Avfuktning av luft i butiker (only in Swedish) (718.59 KB)
Evaluation of an innovative heat exchanger in an open display cabinet
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.
Preliminary study of energy optimization of dehumidification in grocery stores
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.
Innovative heat exchanger in refrigerated counters provides more efficient energy use in stores
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.
Heat recovery with heat pump from food refrigeration system in store
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.
The store that aims for zero energy
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.
Butiken som siktar på nollenergi (only in Swedish)
Doors on open refrigerated counters and adaptation of refrigeration systems in 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.
Washing batteries in refrigerator and freezer furniture
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.
Energy efficient cooling systems in grocery stores
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.
Overcoming barriers to energy efficiency in grocery stores - knowledge of behavior and technology
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?
Exploring barriers to energy efficiency in supermarkets
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 efficiency potentials in professional kitchens - Restaurant kitchens
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.