Vienna fights against tropical heat: New refrigeration machines to the rescue!

Vienna fights against tropical heat: New refrigeration machines to the rescue!

The first tropical nights have already arrived in Vienna - with temperatures above 20 degrees, summer 2025 shows what's to come in the first heat test. This development makes it clear that the city cannot stand idly by. Last year, 53 tropical nights were recorded in Vienna's city center, which is a record. For this reason, Wien Energie has announced that it will invest around 90 million euros in the expansion of the highly efficient district cooling system over the next five years in order to respond to rising temperatures. Today reports that the old refrigeration machines in the district cooling center on Schottenring have already been replaced with new ones. The output will be increased by 1.9 megawatts to a total of 20 megawatts. In addition, a new district cooling center with 6 megawatts of output was inaugurated on Siemensstrasse in Floridsdorf.

But that's just the beginning. Another cooling center with an innovative ice storage facility is currently being built on the MedUni Campus and is scheduled to begin operations this summer. These developments are particularly important because district cooling not only helps to cool buildings, but also causes over 50 percent fewer CO₂ emissions compared to conventional air conditioning systems. Around 200 buildings are already connected to the 30 kilometer long district cooling network, which means a total output of 230 megawatts. These measures are not only a practical response to the heat, but also a step towards climate protection.

The heat island effect

But cooling indoor spaces is only one side of the coin. Urban heat islands pose another challenge. According to an analysis by National Geographic These can be caused by sealed areas and the absence of sufficient green spaces. Old street trees could play an important role here. Dirk Messner from UBA emphasizes how important it is to protect old trees. They not only provide shade, but also absorb CO₂ and thus improve air quality.

Older trees are particularly worth protecting. Studies, including those from the Urban Trees in Climate Change (SiK) research project at the University of Hamburg, show that trees over the age of 40 are better able to deal with diseases, pests and extreme weather conditions. Unfortunately, many urban street trees only live a fraction of their natural lifespan, often because of the harsh conditions in which they must grow. Sealed soils and the proximity to traffic and exhaust fumes take a toll on them. Innovative concepts are needed to give the trees back the vitality they need and thus preserve them as green air filters in the city.

Outlook for summer

Summer in Vienna will not only be a test for the cooling systems, but also for the ecological awareness of the city residents. Under the pressure of rising temperatures and the associated need for cooling, it is clear: Vienna must rethink and act. With the newly established cooling center locations and a strong focus on protecting urban nature, it is important to tackle the challenges of climate change in order to sustainably preserve the living space for all Viennese. After all, the summer of 2025 should also offer a pleasant climate for everyone – indoors and outdoors.