It’s always the same story: Buildings are planned, built, put into operation – and then, for years at a time, when they’re all up and running, no one asks any questions. But adjustments like energy savings don’t necessarily require a huge investment. In fact, for larger buildings with complex systems, there are cost-effective and affordable ways to save energy. These include technical and organizational improvements to system engineering, as well as energyefficient user behavior. The Steinbeis Transfer Center for Energy, Building and Solar Engineering in Stuttgart is offering its support with these types of initiatives.
The European project “Re-Co” (Re-Commissioning – Raising Energy Performance in Existing Non-Residential Buildings) is focusing on the costeffective optimization of energy consumption. It is working on energysaving strategies for 11 complex building types (including hospitals and universities) in eight European countries using minimal investment. The goal is to develop approaches which can be applied to other buildings as well. The project was launched in 2011 and will end in 2014.
As a part of the project, Steinbeis experts in Stuttgart used the Ludwigshafen emergency clinic as a case study for a number of performance optimizations. The clinic uses 25,000 MWh annually, which amounts to a total of 2.7 million euros a year. To date, roughly 8% of the energy costs for heating and electricity have been cut by optimizing the ventilation systems.
A rough analysis revealed that ventilation systems alone consume 45% of the total energy, and account for 54% of the clinic’s total energy costs. For the detailed analysis, the project team gathered information on selected ventilation units in their current working condition and calculated their yearly energy consumption. Afterwards the energy saving potential was calculated through adapting the mode of operation to its current. According to these calculations, the energy consumption in the single units could be reduced by 35% in average.
The clinic was able to achieve these savings by implementing measures with no or low investment costs. The largest potential for savings was found in use-based strategies like automatic shut-off at night, volume flow reduction adapting the actual time profiles in the building management system to its actual use, adapting the conditions to new utilisation of the supplied rooms. Further cost-efficient measures included reducing of the set values of the supply air pressure, exchanging defective damper blades, and checking various volume flow control units.
With its findings at the Ludwigshafen emergency clinic, the Steinbeis Center’s results demonstrated the enormous savings potential for optimizations in ventilation systems simply through adjustments to the building control system. Overall, energy costs were reduced by approximately 170,000 euros a year, with an investment of only 110,000. In ROI terms: the project paid itself off after less than one year.