Passive cooling | component activation and ground/foundation collector

As part of an in-concrete cooling system (component activation in walls and ceilings) of an apartment building in Freiburg a passive system was designed and installed for direct cooling of the thermal storage mass.

The system is purely passive and uses no technical refrigeration. Heat is dissipated directly into the cooling reservoirs of the foundation soil. Through activation of ground / foundation collectors (120m²) the reinforced concrete floors in the living areas can be kept comfortable at stable, moderate temperatures, even during particularly hot months.

The supply temperature of the cheap and easy-to-install system is close to room temperature and operates below measurable convection, thus no uncomfortable active cooling in the room or on the surfaces is perceived despite delivering effective, constant cooling. The system is highly efficient at a very low flow rate.

Activated walls and ceilings can be combined with the complementary heating systems in the floors to create an optimal low-temperature radiation heating.

Services: Energy Concept, heating and cooling load calculations, dynamic simulation of the ground collector, ventilation planning, electrical engineering and control


Rico Fischer Architects

site management:
Architekturbüro 011 Matthias Lange

Technical planning, energy concept:
soap architecture