Künzelsau, Germany
The town of Künzelsau is located in the Hohenlohe region in the north east of the state of Baden-Württemberg, Germany, and has a large demand for housing. Residential property company DH Wohnen GmbH and Aktivhaus build 80 accessible apartments based on 112 wooden construction modules.
Wood is a renewable material that binds large amounts of CO2. The modules are designed so that they can later be disassembled completely and precisely into their input materials. The construction materials used are chosen with sustainability and resource efficiency in mind. The modular construction method also shortens construction times, allowing the urgently needed homes to be handed over quickly. In terms of durability, the homes built with this modular method last just as long as a conventionally built house.
The apartment blocks in this highly sustainable project were planned and built in line with the KfW 40 EE energy standard. This is possible thanks to a highly efficient energy concept that covers the primary energy requirement through large modern heat pumps in combination with photovoltaic systems.
The photovoltaic systems on the roofs of the four apartment blocks even provide a significant proportion of the energy required to run the heat pumps thanks to their regenerative power production. The concept uses four typeMEHP-iS-G07 / 0112air-to-water heat pumps from Mitsubishi Electric that use the outdoor air as an energy source.
Key facts
| Building | Heat Pump and Source | ||
| Location | Künzelsau, Germany | Number of HP | 4 |
| Construction | 2023 | Operation mode | Monovalent |
| No. of apartments | 80 | Model | Mitsubishi Electric MEHP-iS-G07 |
| Level of insulation | Very good | Heating source | Air-to-water |
| Heat distribution | Underfloor | HP only/ Hybrid | HP only |
| Heating sytem | Domestic hot water | ||
| Max. temperature | 65 °C | Type of system | Mix of decentral-central |
| Heating demand | Unknown | DHW demand | unknown |
| Installed power | 4 x 80 kW | Max. temperature | 65 °C |
| Other information | |||
| Climatic zone | Cfb | Refrigerant | R32 |
| Coefficient of Performance (COP) | 3.2-3.5 |
Description of technical concept
The heat pumps of the MEHP-iS-G07 series use Mitsubishi Electric’s own inverter-controlled scroll compressors and EC fans. With a COP of 3.2 to 3.5 as per EN 14511, these units achieve high energy efficiency values. Further environmental protection comes in the form of the R32 refrigerant used throughout the units. It has a GWP value 68% lower than that of the R410A refrigerant still commonly used in this product group. These technical features make the heat pumps perfectly suited for use in comfort applications, where they can truly come into their own.
These units were designed with the heating function as the main focus. Their modular unit structure ensures optimum adjustment in line with the respective capacity requirement for this specific project. This allows them to also be used in local heat networks, for example. Three different modules are available, with seven performance classes ranging from 50 to 110 kW of rated heating capacity and COPs of 3.5 to 3.2 as per EN 14511. A heating capacity of up to 220 kW can be achieved through the optional configuration as a twin module. Encompassing outside temperatures as low as -20°C and hot water outlet temperatures as high as 65°C, the broad application range of these units in heat pump operation means they can optimally meet requirements.
Case study delivered by: Mitsubishi Electric