DUO-TES – Double utilization of above- and underground sprinkler basins as the

To successfully decarbonize the heating sector and integrate renewable energies, efficient thermal storage solutions are essential. However, constructing new storage facilities often entails high investment costs, land consumption, and CO₂ emissions associated with new building materials. The DUO-TES project pursues an innovative, resource-efficient approach: the thermal dual use of existing fire protection and sprinkler infrastructure.

Many non-residential buildings (e.g., logistics centers, hotels, shopping malls) already house underground concrete basins or above-ground steel tanks, typically holding between 400 and 600 m³ of water. Currently, this water is held exclusively for emergency fire suppression. The project investigates the technical feasibility of thermally activating this water (e.g., by raising the temperature by 25 K) to serve as a short-term or seasonal thermal store—without the need for additional land use or significant new construction costs.

Core Project Objectives:

Technical Feasibility: Developing concepts for thermal insulation, material compatibility, and the prevention of cavitation in sprinkler pumps to ensure the system remains fully functional for fire safety at all times.

System Integration: Creating exergy-optimized approaches to integrate these reservoirs into building-internal heating and cooling processes, as well as into existing district heating and cooling networks.

Economic & Ecological Viability: Quantifying energy savings and CO₂ reduction potential while conducting detailed cost analyses to verify the practical applicability and economic benefits.

Comprehensive Collaboration: By bringing together partners from fire safety, plant engineering, research, and energy supply, the project ensures a practice-oriented development that covers the entire value chain, from standardization to operation.