In Vienna, summers are getting hotter. Wien Energie is now relying on climate-friendly building cooling in the new urban development area Donaufeld. A new cooling center will go into operation there in June. It will supply the first 1,000 or so apartments with pleasant temperature control.
Cold water in underfloor heating provides cooling
Cooling is not provided by conventional air conditioning units. Instead, cold water is distributed through the underfloor heating systems that provide warmth in winter. This ensures even temperature distribution in the rooms without the need for additional split air conditioning units.
At Donaufeld, Wien Energie is launching a new cooling center. 66,000 square meters of living space will be cooled in a climate-friendly way.
City councilor explains the benefits
"The number of hot days is increasing, so it is all the more important to ensure climate-friendly cooling methods in the city. The current example in the new urban development area Donaufeld shows how intelligent cooling can be considered from the outset. The first 1,000 residential units are already being supplied with local eco-cooling. Through the additional use of waste heat, residents benefit from a double advantage from the moment they move in: an intelligent and sustainable energy solution in their own home," says Ulli Sima (SPÖ), city councilor for urban development, mobility, and Vienna City Works.
In the underground cooling center, two cooling machines operate with 750 and 500 kilowatts of power. They weigh eleven and thirteen tons and were brought in by crane in the spring. A total of around 66,000 square meters of living space can be cooled with them.
Cooling waste heat is used for district heating
"Cooling is becoming increasingly important for quality of life in the city," says Wien Energie Managing Director Sascha Zabransky. "With the temperature control at Donaufeld, we are relying on an innovative system that combines energy-efficient cooling with sustainable heat utilization: cooling always produces waste heat – and we use this heat for district heating in this plant."
The water flows into the apartments at around 20 degrees Celsius, absorbs heat from the buildings, and transports it away. The advantage: the cooling is gentle and prevents condensation on ceilings or floors.
The waste heat is also utilized. Instead of releasing it into the environment like conventional air conditioning units, it is raised to a higher temperature level and fed into the district heating network. In summer, this can primarily be used to provide hot water for Viennese households.
At Donaufeld, the new system thus provides double relief: cool apartments in summer and additional heat for the grid.
