HEATING AND COOLING WITH THE EXISTING HEATING SYSTEM

Within the building sector, the greatest potential for reducing greenhouse gas emissions lies in existing residential buildings. Furthermore, many of these buildings must be protected from overheating during the summer months. A common solution approach for both problems is being tested as part of the KUEHASystem project in a field test facility in Leipzig with 36 residential units. This approach primarily relies on heat pump technologies, which can provide both heating and cooling. Synergy effects arise particularly in system configurations in conjunction with geothermal probes. Radiators are used for room-side heat transfer in both heating and cooling modes. In particular, the temperature control effect in summer should be evaluated. For comparison, approximately 50% of the comfort rooms on the standard floors (children's rooms, living rooms and bedrooms) were equipped with fan-assisted radiators. In the subsequently converted attic, only fan-supported heating surfaces were used. Replacing the heating surfaces is comparatively cost-effective and allows for a significant reduction in system temperatures when heating and higher cooling outputs in summer. As part of detailed monitoring, all energy flows and relevant temperatures from the central heating and cooling system and all residential unitsare recorded to evaluate the system behavior and the room air conditions. In addition to testing and validating the system solution, the investigations on the object provide detailed results with regard to the control interaction of bi- or multi-valent systems including renewable energy sources.