Challenge
EDEKA Minden-Hannover, one of Germany’s best-known regional companies in the EDEKA group, needed a solution to provide air conditioning for its brand-new company headquarters.
As part of a €150 million project, five large, four-storey buildings are being constructed in Minden-Hannover and the campus will eventually provide workspace for around 2,000 employees. The new campus lies close to a residential area, so the level of noise emissions was a critical factor; the customer’s technical specification stipulated limits of 82dBA. EDEKA has made sustainability a real priority so it was also seeking a solution that would involve the smallest possible CO2 footprint while providing over 3300kW of cooling capacity.
Solution
During the course of the project, Trane worked closely with the specialist HVAC contractor HEIFO from Osnabrück, which was commissioned by EDEKA. The common goal was to develop a solution that addressed EDEKA's two main concerns – achieving the lowest possible noise level and low carbon emissions.
As a result, each of the five new buildings will be equipped with a Trane GVAF 190 XPG series magnetically levitated oil-free centrifugal chiller, each capable of cooling 660 kW. The EDEKA Group's decision in favor of Trane’s solution was largely due to the expert advice given during the preliminary phase which focused on all the customer's requirements.
Trane has extensive experience in providing low-noise solutions and recommended each chiller be housed in special custom-made, sound-insulated enclosures provided by its UK partner. Trane was thus able to provide solid guarantees that noise emissions will not exceed the 82dBA limit.
Results
The original tender document specified another manufacturer and the use of the refrigerant R513a. However, during the decision-making process, the EDEKA Group decided to reduce carbon emissions even further and to order the eligible chillers with a seasonal energy efficiency SEER ratio of 6.28 and the almost zero GWP HFO refrigerant R1234ze. This refrigerant is close to the GWP values of natural refrigerants now.
This decision has increased the initial purchasing cost of the project, but it was important for EDEKA to invest in the most sustainable of all available options. By using R1234ze as the refrigerant, the associated carbon footprint has been reduced significantly compared to the originally advertised R513a.
The first two chillers have now been installed on the completed buildings, and installation of the remaining three chillers will take place as construction progresses. Completion of the entire campus is planned for the first quarter of 2024.
