Fraunhofer - Zentrum Digitale Energie ZDE, Aachen, Allemagne

For the new construction of the Fraunhofer Institute's Digital Energy Center (ZDE), a comprehensive climate concept is being developed that combines minimal carbon emissions during operation with the highest levels of occupant comfort. Together with SEHW Architecture and TEN Engineers, an integrated planning process is underway to create a future-oriented solution that optimally coordinates the façade, indoor climate, and energy supply.
The building envelope features glazing with selective solar control coatings and variable external shading devices. This ensures optimal daylight access to the office spaces while simultaneously minimizing solar loads. The result: reduced heating and cooling demands, high visual and thermal comfort, and an exceptionally energy-efficient building operation.
A concrete core activation system provides comfortable radiant heating and cooling. It operates with moderate supply temperatures, making it highly efficient. During warm summer days, comfort is further enhanced through natural night ventilation via weather- and intrusion-protected window openings and ceiling fans. While the office areas are primarily naturally ventilated, mechanical ventilation systems in interior spaces ensure high indoor air quality.
The energy supply system is based on a four-pipe air/water heat pump. This system shifts heat and cold demand between different building zones as needed, enabling highly efficient simultaneous heating and cooling. The refrigerant cycle includes three heat exchangers: one for heat exchange with air, one for cooling the chilled water supply, and another for heating the domestic hot water. The heat pump can dynamically adjust the energy flow among these three heat sources and sinks.
An additional stratified storage and distribution system optimizes temperature distribution, conserves pump energy, and increases overall efficiency. For example, warm water returning from radiators can be used as a preheat for the ceiling heating system, which operates at lower supply temperatures. A district heating connection handles peak loads, while a photovoltaic system on the green roof sustainably generates electricity.
The result is a building that combines ecological responsibility, economic viability, and future-proof technology—aiming to minimize operational carbon emissions while ensuring comfortable occupancy.