Humboldt Forum - GTN completes project after 10 years
With the installation of the last 20 geothermal probes, the probe field “North 1 West”, including the temperature measuring points, the last construction phase of the geothermal heat source plant was completed and put into operation in October this year. The construction section was previously occupied by the construction site of the Berlin U5 underground railway, which is why construction was only possible after the official opening of the Humboldt Forum.
The Humboldt Forum in Berlin was initially opened digitally on the 17th of December 2020 and started with its regular operation on the 20th of July 2021. For GTN, this opening represents something very special, as it is one of the largest projects in the company's history.
In 2011, GTN was commissioned to design energy piles and geothermal probe fields as part of the building's design planning and shortly before the structural work began. The energy piles are cast in concrete in the foundation piles of Portal 3 under the dome and were thus one of the first technical structures of the entire building.
The special challenge in planning the geothermal probe fields was the foundation of the former Palace of the Republic - the palace trough. About half of the geothermal probes are located in the area of the palace trough, so the approx. 2 m thick reinforced concrete layer had to be drilled through and then sealed again. As it turned out during the drilling work in 2019, the material wear was once again significantly higher than expected.
In the further course of the project, GTN was commissioned with the planning and construction supervision of the energy concept, the heating centre and the building's refrigeration system. An essential component of the innovative and complex energy concept is the integration of geothermal source energy into the overall energy concept of the building.
The Humboldt Forum furthermore has an ice storage facility that supports the compression chillers in generating cooling during peak load periods. The ice storage is loaded at night. This made it possible to reduce the design capacity of the chillers and the necessary recooling plants.
However, the particularly high energy efficiency is achieved by the heat pump system, which uses geothermal energy as the source energy. It is set up in such a way that the building is cooled in summer via component activation and low-temperature systems such as underfloor heating and underfloor convectors are operated in winter.
With the completion of the rooftop café and the probe field “North 1 West”, GTN has been involved in all construction measures of the project from the very beginning to the end. Our involvement in the Berlin City Palace has shaped us over many years and we are proud to have been part of it.