REFRIGERATION SYSTEMS FOR SMALL FOOD RETAIL STORES
04 Sep 2024
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Sometimes small supermarkets and convenience stores may be challenging in terms of system design due to their location, which in many cases is in the centre of cities and towns.
Designing a supermarket does not only entail considering the best solution for displaying the products on the shelves but also matching the technical requirements of the store with constraints and limitations such as the limited space of the property, the admissible sound level, the heat emissions allowed in the neighbourhood, etc. This is whysome technical solutions have today established themselves in the market and represent the ideal solution when installing bulky equipment outside of the store is not feasible.
Breaking the Myth: Natural Refrigerants in Small Retail Environments
For several years in the past there has been a tendency to think that small stores in the suburbs aren’t the ideal playground for solutions based on natural refrigerants. The old F-Gas Regulation (EU) 517/2014 (lately repealed with the new F-Gas Regulation (EU) 2024/573) in fact provided a GWP limit of 2500 for refrigeration systems with a capacity of less than 40 kW, allowing several HFCs, to reflect the fact that, at the time of its publication in 2014, CO2 systems were considered more expensive than HFC-based solutions for small capacity systems.
10 years and several generations of technical solutions based on CO2 later, not only this is no longer the case, but alternative applications of refrigerant R290 propane have also been introduced, that guarantee sustainability, efficiency and safety.
Besides the increasing penetration of small capacity CO2 refrigeration condensing units, currently made available by several manufacturing companies mainly in Italy and Japan and widely used across Europe, there has been a considerable growth of different systems using R290 propane. In fact, the revised EN 60335-2-89:2022 has increased the permitted refrigerant charge to 500 grs per circuit, in recognition of the fact that propane is pivotal in ensuring the growth of natural refrigeration in new market segments, particularly small stores.
More often than not, small stores located in city centres, like convenience or proximity stores, do not enable the installation of the refrigeration rack outside, as they might not have the necessary protected space close to their external walls or the noise and exaust heat produced by the equipment would hardly be accepted within the limits foreseen by the local building codes. In similar situations the preferred choice are either plug-in or integral cabinets, air or water cooled.
Integral Cabinets: an all-in-one solution
While most people know what a plug-in cabinet is for the numerous examples in the food and beverage, ice cream, frozen products sectors, an integral cabinet is a refrigerating appliance with a direct sales function, like a multideck cabinet, a serve over, a glass-door freezer, or else, typically available as remote, to be connected to a centralised refrigeration system, to which a dedicated refrigeration circuit is built within and sized specifically on its cooling requirements.
Integral cabinets are a popular choice for commercial refrigeration because they can be plugged in and operated immediately. Using and operating them does not require much technical knowledge. Essentially, integral cabinets and freezers are self-contained units, meaning they have everything they need to run built into them. All elements of the refrigeration system, from the condenser to the evaporator, are built within the cabinet.
As soon as it’s plugged in and running, an integral unit is ready to keep food items perfectly refrigerated. The cabinet is easy to use, convenient and compact, making it suitable for various cooling applications, and satisfies all the needs and the requirements of small surface stores.
In a self-contained or integral refrigerator, you may find the evaporator on top and the condenser at the bottom, or viceversa, connected by tubes to form a closed circuit sealed at the factory, pressure tested and charged with R290 refrigerant, in compliance with safety technical standards, like the EN 60335-2-89:2022.
These kinds of refrigerators offer several advantages to end users:
• Installation is very easy and not costly and does not require specific refrigeration skills or a frigorist technician;
• The compressor and condenser are built into the system, so there’s no need to run long lines from/to the power racks and the condensers;
• They are extremely convenient to use and do not require any store surface for the technical equipment nor any space outside of the building;
• If they need to be moved, they can easily be relocated.
The heat generated by self-contained units, whether plug in or integral, is not dispersed into the environment outdoors but is recovered directly and used to heat the store in winter thus contributing to the store’s overall efficiency. In summer the exaust heat from the refrigerators needs to be either compensated by the air conditioning system or rejected outside through the store ventilation.
Waterloop: Recovering heat the cool way
An alternative way of using the important resource that is the heat produced by the refrigerators is represented by water-cooled integral cabinets, also known as waterloop cabinets.
Here the air finned-type condenser typical of plug-ins and air cooled integral cabinets is replaced by a water cooled condenser, such as a small plate heat exchanger, that allows the heat to be transferred from the refrigerant to a fluid, such as water or glycol.
In this case a water connection system supplies each cabinet with chilled water. The heat is collected by the water loop and can be supplied to a heat pump or rejected in the open air by a dry cooler typically placed on the roof.
The integral water cabinets come as factory-made hermetic units built into the cabinets, and this ensures sustainability, safety and best-in-class performance. Installation is simplified as these units are also factory charged and only need electrical and water supply to operate, there again eliminating the need for a machinery room, thereby freeing up more sales area.
Besides CO2 condensing units, today more and more simple and compact, both integral air and integral water cabinets these days represent the ideal choice for small supermarkets, simply because they are extremely efficient and most importantly are plug&play solutions.
Weighing the options in terms of sustainability and Total Cost of Ownership before purchasing is evermore essential. Therefore, nowadays more and more system providers can generate safe and reliable data that can compare different solutions based on natural refrigerants specifically designed for small surface stores.
