Natural ventilation strategies for nearly – Zero Energy Sports Halls

Abstract: In line with the article 9 of the EPDB, member states shall ensure that all new public properties are nearly zero energy buildings (n-ZEB) by December 31, 2018. Sports buildings account for a significant share of the European building stock consumption. More than half of their current energy needs are related to lighting, and a relevant energy use is due to domestic hot water. This work aims to test different energy measures to design nearly zero energy sports halls in Mediterranean climates. Under a holistic approach, the design of the base case sports hall includes the implementation of passive strategies in combination with renewable energy and energy efficient systems in order to meet the n-ZEB conditions. However, a special focus is put on the study of the sports hall ventilation requirements. A natural ventilation system is proposed as an alternative to a traditional mechanical one. The effectiveness of the analyzed ventilation strategies is validated using TRNSYS, a dynamic simulation tool. Therefore, natural ventilation impact on thermal comfort, air quality and energy needs is estimated. A cost effective evaluation is done following the methodology proposed by the European Directive. Additionally, the study is complemented with a short period of measurements in a selected existing facility according to which poor indoor air quality is the main cause of users discomfort during period of maximum occupancy. The obtained results show that the combination of reduction of thermal transmittance of the envelope, optimization of the windows surfaces, façades orientation, introduction of shading devices, installation of energy efficiency systems as LED lamps and use of natural and night ventilation, are advantageous for the reduction of heating, cooling and artificial lighting demand. Overall, consisted primary energy savings are achieved. Moreover, the described strategies ensure indoor thermal comfort, minimizing the period of overcooling and overheating, and provide good air quality conditions for most of the occupied time along one year simulation. Finally, it is verified that the PV system integration positively affects the sports hall performance toward n-ZEB standards.