Can buildings be cooled with environmental energy? Yes - with the aid of thermo-active building systems. Conventional chillers become unnecessary if buildings are planned and built in an architecturally and physically energy-optimised manner. And if using thermoactive building systems, the building's own storage capacity can be utilised for temperature compensation, and activated via natural heat sinks such as the ground, ground water, or the cool night air. Since the 1990s, more and more buildings are being cooled with these systems - and heated as well.

But how much flexibility remains in the utilisation of buildings? How energy-efficient are the thermally inertial surface cooling and surface heating systems? What are the prerequisites for the concept to be economically viable? What level of comfort is actually achieved? These questions are discussed here, also on the basis of three new buildings from the monitoring programme "Energy-Optimised Construction" (EnOB), a research initiative of the German Federal Ministry of Economics and Technology (BMWi). Here, building and energy concepts, as well as new materials and technologies, are extensively tested under real operating conditions, and are assessed according to scientific criteria.

With this Themeninfo brochure, we present a substantiated initial assessment of concrete core temperature control, which is a commonly implemented thermo-active building system.

The energy consumption for heating, cooling, ventilation and lighting, analysed in terms of primary energy, is below 115kWh/m² p.a. in all the buildings presented here, and is 2 to 3 times lower than the consumption values of today's standard new office buildings. The thermo-active building systems perform so well in this regard because natural heat sources and heat sinks can be utilised.