How Energy Efficiency Measures Influence and Simplify the HVAC Design at Austria's biggest Plus-Plus-Energy Office Building

Abstract

Due to the precisely optimization of up to 9300 building components and an optimized passive house envelope, the primary energy demand has been reduced to a minimum. The consequent implementation of plenty of energy efficiency measures enables less HVAC efforts by simultaneously maintaining high level thermal quality requirements. Therefore, an optimized heating, cooling and ventilation demand simplifies the entire HVAC system to meet all challenges and requirements regarding a comprehensive refurbishment towards a plus-plusenergy office building. The implementation of a CO2 driven and real occupation based ventilation system with a variable and optimized air rate, is only one key element towards user satisfaction, HVAC simplification and integral planning stages. Furthermore, an interdisciplinary team of experts, including a scientific team of the TU Wien, have been used the instruments of holistic planning approaches and a simulation based decision making process during all stages. The primary energy balance at Austria’s biggest plus-plus-energy office building covers not only the energy demand for it´s entire operation, but also for the energy demand caused by all it´s occupancies. As a result of the reduced area for the HVAC distribution and generation, this building benefits of an additional conference room at the top of this building as well as an additional night ventilation system. By considering the general issue of complex refurbishments within a city, the concept and the approach of this plus-plus-energy office building can be seen as a best practice example in terms of facing future urban challenges.