Wien Energie commissions eighth district cooling plant
28th July 2025
AUSTRIA: Wien Energie has commissioned a large-scale €22m district cooling plant using ice storage on the MedUni Mariannengasse campus in Vienna’s Alsergrund district.
The building complex is the eighth such cooling plant in the Wien Energie network, but the first with an ice storage system. This 17.7MW system also incorporates a waste heat recovery heat pump, ensuring particularly resource-efficient cooling.
Cooling is required all year round, even in winter. In summer, the waste heat from from the cooling production will be utilised to provide the entire heating requirements of the building.
Compared to conventional air conditioning systems, the district cooling centre at the MedUni Campus is expected to save 1,000 tonnes of CO2 emissions annually.
The 6MWh ice storage system, comprising a 10m-long insulated container, is designed to cover peak consumption and allows the chillers to be used more evenly and thus more efficiently. The ice storage system is charged at night or when consumption is lower.
When fully completed, the site will have three chillers powered by green electricity, a heat pump and an absorption chiller powered by district heating.
District cooling is generated in separate central units with highly efficient chillers. The water, cooled to around 5-6ºC, is transported to customers via insulated pipes and distributed throughout the buildings via the in-house cooling systems.
The water absorbs heat from the building and transports it away. Re-cooling is also carried out centrally, using river water where possible.
MedUni Vienna is one of the world’s oldest and most renowned universities in medical research, university medical care and research-led training for future doctors.
The MedUni Campus Mariannengasse offers space for 2,000 students and 750 employees. In addition to lecture halls, practice rooms and learning areas, the building offers the best possible conditions for medical research and teaching on a total of 35,000m2 of floor space.
The listed existing building is being renovated and serves as a link between the old and new buildings. In addition to district cooling, the energy concept includes low-temperature heating, a district heating connection and highly efficient heat recovery from the central ventilation systems, including laboratory ventilation.
