So there hasn’t been much going on in Barbara Kujawski’s living room for a long time. She is standing in the hallway of her apartment on the ground floor of a residential complex in the south of Duisburg that belongs to the real estate group LEG. In the living room next door, the North Rhine-Westphalian Minister of Construction, Ina Scharrenbach (CDU), is looking at what Kujawski should heat with in the future: the device on the wall looks like a classic air conditioning system, a few representatives of the European division of the Japanese group Mitsubishi Electric explain it Difference. Because outside on the wall there is another system that turns the whole thing into an air-to-air heat pump – and should make the energy supply cheaper for the tenant in the future.
In a pilot project in Leverkusen, Radevormwald and Duisburg, the Düsseldorf-based real estate group is currently testing whether such heat pumps are suitable for heating and whether tenants will accept them. After all, the air conditioners on the wall have that American motel charm that puts some people off at first. However, the technology is now so advanced that you don’t necessarily have to sit in a draught, and the heated air is also efficiently heated. “The devices have about the same performance as a toaster, but of course for several hours a day,” says Mirko Ebbers, who is responsible for everything to do with sustainability at LEG. “But you generate a lot of heat from relatively little electricity.”
Saving despite higher electricity costs
LEG has installed the air-to-air heat pumps in unrenovated apartments, in vacancies and, like here in Duisburg, in newly renovated buildings. “Our goal was to use different heat sources to find out how this affects energy consumption and customer satisfaction,” says Volker Wiegel, the LEG board member responsible for operational business. “Previously, gas was significantly cheaper than electricity,” says Wiegel. “But now the situation is different: We did the math and even with higher electricity consumption, the tenants save costs.” Even in the renovated apartments, the burden on the residents should not increase even after a rent increase.
The conversion to the air-to-air heat pump could make sense, especially in North Rhine-Westphalia, of 4 million gas heating systems nationwide there are 1.2 million in the most populous federal state. LEG has 20,000 apartments with such gas floor heating systems in its portfolio. “This is the first technology that enables the complete replacement of broken devices. We can exchange within a day, which is particularly great where gas heating is currently installed,” says Wiegel. For this you need an electrician who has also made a cold certificate.
Compared to the classic heat pump, which is currently the subject of much talk and which is usually located in the basement, installation is quicker – after all, questions about the hydraulics and installation space do not have to be clarified, as is the case with the air-water heat pump. However, the speed is also due to the fact that there has hardly been any demand so far and the waiting times for new devices are therefore much shorter. In Germany, Mitsubishi Electric has so far only installed such devices in commercial properties, and German manufacturers have not yet specialized in these systems. In Scandinavia or Japan, on the other hand, they have been widespread for a long time.
Also a strategy for decarbonization
For LEG, this is not just a test run to show which alternatives to gas work. “The technology is one of the best for decarbonizing quickly,” says Ebbers. Even electricity that is generated by burning lignite to generate heat using an air-to-air heat pump is more environmentally friendly than gas. As soon as you only use electricity from renewable energies, the heating is CO2-neutral. “This also allows us to refurbish the buildings in the usual cycle,” says Ebbers.
The industry is watching with excitement what is happening in Berlin in the amendment to the Building Energy Act (GEG), which will be negotiated in the coalition committee on Sunday. NRW Building Minister Scharrenbach says about the plans: “The spaceship Berlin has lost contact with the ground”. Of course, this also includes subsidies for heat pumps. Large companies are more likely to be able to cope with the many requirements, but LEG board member Wiegel fears that they will be overwhelmed: “If we want to stick to the climate path, we also have to think of the dentist or the master craftsman who wants to convert his six-party house to make provision for old age.”
