Monitoring and Optimization of Building Operations of a Low-Energy School Building

Abstract

The ambitious design and energy concept of the new Gebhard-Müller-Schule (GMS) school building in Biberach/Riss, Germany proved itself during the first three school years of operation. The intended target value of 30 kWh/(m2a) overall heating energy consumption was almost met during the second year of operation in 2006 and finally achieved in 2007, due to well-working optimization measures, which were identified through monitoring of the building operation. Heating and cooling energy is mainly provided by a groundwater well plant, which serves as a heat source for two heat pumps as well as a direct cooling source for supplying the radiant heating and cooling system that is integrated in the concrete floor and ceiling slabs (thermally activated building component systems – TABS). Indoor air conditioning and server room cooling are also connected to the groundwater cooling system. The main component of the groundwater well plant is a submersible pump on the bottom of the well which is located underneath the building. The pump supplies the building reliably with geothermal energy, but also consumes a significant amount of electricity. Monitoring and optimization of the building’s operation, funded by the Federal Ministry of Economics and Technology in Germany, revealed fundamental findings about the operation of the system and the possibilities to improve the building’s performance. Since 2005, the measurements show a continuous increase in efficiency, particularly in the field of auxiliary energies. This significantly increased performance clearly shows the potential of the use of groundwater for heating and cooling purposes and of thermally activated building component systems. In addition the measurements reveal the sensitivity of the system efficiency in terms of operating parameters.