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Administration buildings . High-rises


Scope of supply

Planning and site management for the technical supply installations for Beha Innovation GmbH in a new building, which includes a workshop area for mould manufacture, covering the trades/systems sanitation, heating, compressed air, air-conditioning and cooling, chilled ceilings, I&C/BMS, high and low-voltage systems, and geothermal plant.

·           Dedicated use of geothermal heat with over 35 geothermal probes for cooling and heating

·           Office cooling by means of 1,600 sq.m of chilled ceilings supplied solely from geothermal probes

·           Heating by a 200 kW heat pump plant using exclusively geothermal probes.

·           Machine cooling using geothermal probes and reversible heat pumps

Beha Innovation GmbH chose “Erdwärme, NaturenergieGold” from its regional supplier as the alternative energy for its new building, both from an ecological point of view, but also to be seen as a trailblazer for innovative technology.

For this 35 geothermal probes were inserted into the ground at a depth of about 120 metres. They draw energy from the ground that has been absorbed from the sun.

In order to ensure the continual, alternating use of the ground for heating and cooling, and to optimise the heating/cooling operations, the geothermal probes were bored to different depths. The depth patterns were determined on the basis of several simulation calculations for the heating and cooling energy flows, and with careful consideration of the geology.

The geothermal probes are plastic tubes with a diameter of 32 mm, which are filled with a water/glycol mixture. Closed-circuit circulation heats or cools the water in the probes to a temperature in the range from ca. +16°C to -5°C.

The geothermal probes are used throughout the year, for cooling of the whole building in summer by means of about 1,400 m² of chilled ceilings, and for cooling the production plant; in winter they are used with a heat pump as the sole source of building heating.

In summer operation the water that circulates through the thermal probes is used directly, at a temperature of ca. 15°C, for cooling the offices without further energy-related measures. For process cooling in summer, a downstream cooling plant further reduces the temperature from 15°C to 10°C. In winter, a hydraulic switch diverts the primary circuit of the heat pump for process cooling.

Because such an installation requires great planning reliability, IB Liebert entered the complete building data in a suitable building simulation program. This enabled the simulation of the behaviour of the building with the necessary cooling and heating loads over the course of a day at appropriate positions of the sun. The geothermal probe installation could thus be designed exactly to suit the building and the local ground conditions.

Because the ground conditions are a decisive criterion for the heat transfer capacity of the geothermal probes, the geological planning office Systherma and their responsible geologist, Dr. Walker-Hertkorn, were engaged as consultants.

Systherma analysed the behaviour of the ground over a period of 40 years using a complex simulation program, on the basis of the necessary energy flows in and out of the building for heating and cooling. This analysis was carried out in close cooperation with our office.

In addition, with the plant in operation, the appropriate feed and return line temperatures were continually measured and optimised using the building management system, so that even at peak-load conditions the necessary power can be withdrawn from of fed into the ground.

So as to be able to observe the storage tendencies of the ground, and thus to be able to react to thermal changes in good time, three temperature sensors were installed in the ground at depths of 40, 80 and 120 metres.

The interplay of heating and cooling using the geothermal probes achieves a synergy effect, which warms the ground slightly in summer so that it is available as a heat reservoir in winter. In winter the reverse is the case and the ground builds up a reservoir of cooling for the summer.

This interplay is extremely important for a continuous, stable and balanced ground temperature, so as to ensure that the necessary, planned temperatures are always available from the geothermal probes for winter or summer operation as appropriate.

The cost-effectiveness is an important decision criterion for any investment. Cost-effectiveness calculations are part of the standard spectrum of services offered by IB Liebert. The objective is to present the client with comprehensive, transparent decision guidelines for every investment.

Illustration: @ Beha Innovation GmbH, Glottertal; IB Liebert, Hüfingen

Glottertal near Freiburg

Beha Innovation GmbH

Realisation period
2005 - 2007 

4,100 m² gross floor area

Service phases
HOAI § 73, Phases 1 - 9