In coporation with the Institute of Thermal Engineering at the Graz University of Technology arsenal research applied expert tools in order to support the ENERGYbase planning team by providing scientific expertise. Herewith the energy performance of ENERGYbase office building has been considered and analysed in an early phase of the planning procedure and additionally some important advises and analysis in order to optimise the energy system performance were

developed and conducted. The scientific support actvities were based on using simulation expert tools and were mainly focused on following emphasis:

• Scientific support of an integrative planning procedure:

Challenging is both the complexity of planning and the integration of non-standard technologies and systems in such a building project. Therefore an integrative planning approach has been applied in order to achieve the ambitious ENERGYbase project targets by involving scientific energy experts in the communication process from the beginning on. arsenal research as a centre of excellence for sustainable buildings and energy systems has scientifically supported the planning team and did essential contribution and advice in time, especially related to the HVAC concept and renewable energy systems. The scientific support was mainly based on operating expert tools — like transient building an system simulation and computational fluid dynamics CFD (2)- and herewith generated results and their comprehensive analysis and intepretation have been presented and discussed on project planning meetings.

• Assessment of the energy and thermal building performance:

The overall ENERGYbase concept meaning both the architectural and energy system design aims to achieve high values of energy efficiency, to use of renewable energy sources and to provide an strongly improved user indoor comfort. In order to assess the thermal building performance of the office building arsenal research applied the simulation environment TRNSYS (3) and developed a comprehensive and flexible building modell. Due to this approach the impact on the ENERGYbase building performance by changing energy and/or comfort relevant parameter could be quantified based on the current status of planning. Consequently a continious assessment of the energy building performance improved the quality of planning, especially with regard on pre-defined energy and comfort targets.

• Detailed analysis on selected energy systems

The indoor temperature of ENERGYbase offices is controlled by thermal mass activated construction elements. Due to the fact that the heat transfer of the thermal mass activation is limited arsenal research modelled and simulated this low temperature distribution system in order to confirm whether the internal and external loads of ENERGYbase offices can be rejected or additional equipment has to be integrated. Furthermore by using transient system simulation arsenal research gave advice which control strategy of the thermal mass activated construction elements results into a low energy demand and a sufficient indoor comfort.

The indoor humdity of ENERGYbase offices is controlled by an air-conditioning system which uses a solar thermally driven desiccant evaporative cooling technology (DEC). This solar-assisted air-conditioning system is an non-standard system which uses solar heat to regenerate the dehumidification unit. Because the DEC system technology is characterised by thermodynamic limits arsenal research modelled and simulated the system performance and assessed the overall system design and concept.

• Detailled comfort analysis of south oriented offices

The architectual ENERGYbase design and the concept of the south faced facade allows a high ratio of daylight use in the entire office building which enables a significant reduction of electricity demand for artifical lighting. Additionally special internal jalousies guide daylight into the deepness of the south offices which improves daylight comfort. arsenal research did scientific studies on the thermal comfort for an future ENERGYbase users which would be placed near to the

south faced facade. Different types of internal jalousie were modelled and investigated regarding their impact on thermal comfort.