T&K Invest GmbH developed a simulation-based energy supply concept for Mobau Müller Baustoffkontor GmbH in Bannewitz for the construction of a new, modern retail and office building with a heated warehouse. The building comprises around 1,340 m² of usable floor space and was energy-optimised on the basis of a dynamic building simulation to ensure cost-effective and future-proof operation.
A particular challenge was posed by the limited electrical connection capacity of the 50-kW mains connections, which could not be expanded. This must be sufficient to power, across the entire site, four forklift trucks, a fresh concrete dispatch point, a paint mixing machine, servers, lighting for around 4,000 square metres, the ventilation system, as well as the building’s heating, cooling and hot water supply. The aim was to minimise the building’s energy requirements whilst ensuring sufficient capacity for future charging infrastructure and operational loads.
At the heart of the energy concept is a brine-water heat pump with a ground-source heat collector covering approximately 1,200 m². In combination with concrete core activation and underfloor heating, the system ensures an energy-efficient heat supply whilst also enabling passive building cooling in summer – entirely without the need for an additional chiller. A ventilation system with over 80 per cent heat recovery further reduces heating energy requirements.
The concept is complemented by a 60 kWp photovoltaic system (with a 50 kW inverter), which generates around 66 MWh of solar power annually. This allows a large proportion of the electricity demand to be met directly on site, significantly reducing the amount of electricity drawn from the grid. Overall, the building has an annual heating energy requirement of around 50 MWh, whilst the heat pump requires only an electrical connected load of approximately 10 kW, despite a building heating load of around 74 kW. Compared with a comparable air-to-water heat pump, this represents a reduction in electrical connected load of around 45 per cent.
The result is a cost-effective and climate-friendly energy concept with low operating costs, high security of supply and optimal conditions for the integration of electric mobility as well as future expansions.
