A Sustainable REFRIGERATION Technology

The CO₂-powered AC system, which was developed on the campus of the University of Bayreuth, releases considerably less greenhouse gas than conventional air conditioning systems, and exemplifies the great ecological potential of this type of system. As a demonstrator, it will serve vocational training in the field of air conditioning and refrigeration technology in Kulmbach. The project was funded by the Bavarian State Ministry for the Environment and Consumer Protection.

Detailing on the project, Alexander Battistella, Director of BSZ, said, “The cooperation between the University of Bayreuth’s ZET and the Vocational School Centre Kulmbach was supported by great commitment from all involved. The air conditioning system installed recently gives pupils at BSZ access to the most up-to-date know-how research has to offer. As future specialists, they can use this system to develop an understanding of important energy technology issues that need to be solved while complying with strict ecological requirements.”

A first test run recently met with great interest among the students of BSZ. In class, they learned about the ecological advantages of CO₂ as a refrigerant and learned about current changes in EU law aimed at increasing climate protection.

The construction of the plant on the campus of the University of Bayreuth was part of the project “ZukunftKlima – Entwicklung zukunftsfähiger Klimatisierungskonzepte” (FutureClimate – Development of Sustainable Air Conditioning Concepts) at the Centre for Energy Technology (ZET) of the University of Bayreuth. The Bavarian State Ministry for the Environment and Consumer Protection funded the project to the tune of approximately € 240,000 for three years. The research work concentrated on the use of environmentally friendly refrigerants for air conditioning in buildings. The focus was on the use of CO₂ as a working medium in decentralised air conditioning systems.

In comparison with the conventional refrigerant R410a, the ecological balance of CO₂ air-conditioning systems is most impressive. Assuming weather and climate conditions typical for Germany, the greenhouse gas emissions of air conditioning systems can be reduced by around 26% through the use of CO₂. If the currently forecast expansion of renewable energies in the electricity sector is taken as a basis, the CO₂ air-conditioning system will even make it possible to reduce greenhouse gas emissions by 49% in 2050 compared to the current state of the art. Moreover, the studies at ZET showed that control strategies used in the operation of air conditioning systems can significantly influence greenhouse gas emissions.

Highlighting their activities, Prof. Dr.-Ing. Dieter Brüggemann, Director of ZET, said, “Researching and testing innovative energy technologies that are highly efficient in economic terms, and at the same time sustainably promote climate and environmental protection, has been a central field of work at the University of Bayreuth’s ZET for many years. In a large number of projects, we work closely with companies and public institutions in Upper Franconia, as the recent commissioning of the CO₂ air conditioning system in Kulmbach proves. I am very pleased that, with this pilot project, we are building a bridge from university research to the practical training of pupils passionate about energy technology issues, who see their professional future in this field.”