Migros Surseepark

A REMODELING THAT LEVELLED THE WAY TO THE FUTURE

The Migros supermarket in the shopping centre “Surseepark” has been remodeled for four months and was made ready for the future. Backstage, an innovative HVAC-project was implemented: A reversible air/water CO2-heat pump provides sustainable air-conditioning and heating for the whole building. For the refrigeration needs of the Migros supermarket and the Migros restaurant, a sophisticated CO2 refrigeration plant has been installed.

Late summer 2019, the reconstruction of the “Migros Surseepark” has been completed. The shopping centre in Sursee near the city of Lucerne, has three different buildings, whereof two were undergoing reconstruction. The sales area of the supermarket is 4’500m2 and is located on the ground floor. The Migros restaurant is situated on the first floor with an area of approx. 600m2. The refrigerating plant and the reversible air/water heat pump is located on the second floor. During the remodeling of the site, Migros has provided a temporary store with a sales area of 1’500m2 to its customers.

OIL HEATING WAS YESTERDAY

The existing heating system operating with oil and air-conditioning installation with synthetic refrigerants were replaced by two reversible air/water CO2-heat pumps with ejectors, providing an overall heating- and cooling capacity of 1.2 MW. The new system – the first of its kind – heats during wintertime and delivers coolingenergy during summer, resulting in a significant reduction of environmental impact. The financial contribution by the federal office of energy (BFE) and foundation “myclimate”, which co-financed the installation in terms of a project demonstration, shows the lighthouse character of that project. The idea was not only to establish such concepts throughout Switzerland but also across the HVAC-related industries. With this investment, important fundamental knowhow as well as unique experience regarding the Swiss energy strategy 2050 are being collected. During the concept evaluation it was an important concern to Migros to emphasize sustainability, namely the reduction of greenhouse gas emissions, the reduction of energy consumption and the application of natural refrigerants

PIONEER IN A NEW TECHNOLOGY

One of the most significant advantages of CO2 as refrigerant is the fact that high water temperatures for heating purposes can be achieved with very little rise of energy consumption. This characteristic makes CO2 an efficient solution for heating systems with high temperature differentials or for applications with large demands of hot tap water. Hence, CO2 suits especially existing buildings with traditional heat distribution systems. The remodeling of existing building is common practice in Switzerland. Due to the high settlement density as well as the good and solid structure of existing properties, there are comparatively few new buildings being constructed. The combination of heating and refrigerating in one single system allows a compact construction, which is an advantage especially for existing buildings. A smart integration of heat-exchangers allows utilisation of heating-energy simultaneously with providing cooling energy e.g., the building can be air-conditioned and at the same time produce hot water without any additional effort. Since the first successful implementation of ejectors in commercial CO2 refrigeration systems back in the year 2013, it is nowadays also possible for CO2 air-conditioning systems operating with high outside temperatures to achieve comparable COP’s as with synthetic. The implementation of ejectors increases the energy efficiency between 20% and 30%, thus opening the door for new application fields.

The capacity of the refrigeration system respectively of the reversible CO2 heat pumps are based on the demand of the retail trade:

• Refrigerating capacity MT-System: 142 kW (135m of cabinets and 8 cold rooms)

• Refrigerating capacity LT-System: 70 kW (40m of cabinets and 4 freezer rooms)

The gas-coolers of the plant as well as the heat pump/air-conditioning are situated on the roof. With this project, Migros takes a pioneering role. Despite the fact that basically no experience was existing for such sophisticated concepts, Migros supported the solution with the lowest greenhouse gas emission and lowest CO2-footprint. In addition, Migros is willing to share know-how and experience gained within the retail trade, thus making a valuable contribution for a better environment. Last but not least, Migros accepts higher investments costs to support sustainable and trendsetting technologies.