Downloadliste
Revitalization of supermarkets
Today's supermarkets need to use air conditioning solutions that are flexible, economical, and future-proof. Building technology is becoming an increasingly important factor for success—provided that it is designed holistically and perfectly coordinated. Kai Lücke, Head of Air Handling Unit Projects at WOLF in Mainburg, explains the challenges facing the industry and the path to sustainable solutions.
1. German grocery chains are reinventing themselves. Not only are their stores becoming increasingly upscale, but they are also investing heavily in decarbonization. Where is ventilation technology headed?
Kai Lücke:
Ventilation technology is also becoming increasingly important in spacious stores, as it is an integral part of sustainable store strategies that combine environmental responsibility with a pleasant shopping experience. Ventilation technology is thus becoming an important component of modern, sustainable retail concepts. It reduces both heating and cooling energy requirements, enabling substantial savings in both new and existing buildings.
2. What requirements do supermarkets generally place on ventilation technology?
Kai Lücke:
The targets are low CO₂ emissions, high energy efficiency—both of which also equate to low energy costs—and a stable, draft-free temperature and humidity profile across all zones. This applies both to areas in the supermarket itself and to concessionaires. For example, a pharmacy should not be affected by the neighboring kebab shop, and the checkout area has different requirements than, say, the fresh food or meat counter. Since commercial refrigeration is the largest consumer of electricity in the market and a supermarket is organized into temperature zones, the HVAC technology must be closely integrated with the refrigeration technology. Adaptable solutions also take into account the strong fluctuations in visitor frequency over the course of the day and week, with changing requirements for heating, cooling, and fresh air supply. The main standards are VDI 2082 (sales outlets), VDI 6022 (hygiene), and VDI 3803 (structural/technical requirements).
3. There is not unlimited space available for new construction on proverbial “greenfield sites.” What challenges does the retail sector face when commercial properties are revitalized?
Kai Lücke:
The F-Gas Regulation means that, as intended by the EU, established refrigerants with a comparatively high global warming potential (GWP) are gradually being replaced on the market by low-GWP refrigerants. This presents manufacturers and operators of air conditioning systems with the challenge of having their entire technology put to the test. Many operators not only want to change the refrigerant, but also reduce it and, where possible, keep refrigerant lines out of the sales area.
However, if, for example, water loop systems and closed instead of open refrigerated cabinets are used, an existing ventilation system will in most cases no longer work satisfactorily because the room air parameters change. Open shelves with double cold air curtains generate different air and humidity loads than closed wall-mounted refrigerated shelves with doors. If the refrigerated shelf is not sufficiently dehumidified, the windows of the refrigerated display cases fog up and frost forms in the frozen food area.
In addition, stores have to deal with widely varying loads: Sunlight can mean that even at outside temperatures of around +14 to +18°C, heating is needed in the checkout area, for example, while other areas need cooling at the same time.
Another challenge can come from municipal heat planning. For example, cold and/or hot water networks in district heating priority areas enable completely new concepts.
4. Is there a proverbial magic formula for food retailers to reconcile these issues?
Kai Lücke:
Revitalizing markets usually means looking at each case individually. In general, existing buildings pose individual challenges due to structural considerations, local building regulations, and neighboring buildings. Specifically in terms of ventilation technology, there is no universal solution, as the technical situation in each individual market varies greatly. In recent years, for example, technically mature solutions have been installed in parallel in many markets in the industry. These now often “suffer” from the F-gas regulation. At the same time (up to the present day), however, innovative pilot projects have also been implemented.
Currently, the overarching goal is to keep the electrical energy used “working” in the system for as long as possible, i.e., to focus meticulously on heat recovery.
5. What role do holistic concepts play among decision-makers?
Kai Lücke:
Decision-makers are increasingly focusing on the long-term life cycle: markets are being planned and upgraded for the next 40 years, with sustainability and operating costs at the forefront. Systems with high partial load efficiency, modular scalability, quick installation, and low operational complexity are preferred. Holistic concepts therefore consider the building envelope, refrigeration technology, HVAC units, control systems, and zoning as a continuously controllable system.
These intelligent system architectures integrate heat and cold storage, door air curtains, climate ceiling units, ventilation systems, and combined refrigeration systems into a single control network. The more system components interact precisely in a sensor-controlled manner, the more robust the overall concept. In the event of a partial failure of individual components, overall functionality is maintained.
Holistic concepts often separate the functions of ventilation and cooling because the air exchange rates for hygiene are usually lower than the air volumes required to cover the load. This allows ventilation units to be designed smaller and more efficiently, while decentralized systems such as fan coil units take over room conditioning. Reversible heat pumps with natural refrigerants are increasingly taking over the function of heating and cooling. They can also use the waste heat from refrigeration and freezer units, service counters, and cold rooms as an energy source. If heat and/or cold are stored, peak loads can be better absorbed.
A four-pipe water loop system for extracting heat from commercial refrigeration is particularly noteworthy here. The waste heat from the refrigeration unit compressors then serves as a constant source of energy for a reversible heat pump. This is capable of providing either hot or cold water. Stored in buffer tanks, this means that both cooling and heating are available to the individual zones at the same time. Dehumidification can also be carried out on a zone-by-zone basis.
6. How do you proceed when advising customers on revitalization?
Kai Lücke:
Good consulting always begins with listening and understanding in order to truly grasp the requirements, challenges, and goals of our customers. In the next step, we work together to develop the right solution that fits the customer's corporate philosophy and incorporates the latest technical developments and trends in order to uncover any dormant potential. As a system provider for heating and air conditioning, WOLF has a comprehensive range of components that can be combined to create holistic and sustainable solutions. This results in customized concepts that are precisely tailored to a market and create long-term added value..
Further information on WOLF air handling units can be found at: https://www.wolf.eu/en-de/professional/ahu-products