An evaluation of energy efficiency measures in a Turkish campus building for thermal comfort and economic risk

Abstract

As new and retrofitted Turkish buildings adopt stateof-the-art energy efficiency measures, hidden risks associated with compromised thermal comfort and disappointing returns on investment could go unnoticed unless a building is subjected to an uncertainty and risk analysis. Standard deterministic predictions are not sufficient, as they do not capture the effects of uncertainty and variability with regard to local microclimate conditions, physical parameters, and discrepancies in the model formulations, also known as “model form uncertainties”. In this paper, we analyze the impact of uncertainty on the performance of a Turkish campus building. We examine the risk that an energy efficient design that is accepted because of the positive results of a conventional energy simulation, causes unacceptable discomfort and unsatisfactory returns on investment. The results of a comprehensive uncertainty analysis shows that these risks exist in certain areas and not in others. The predicted annual output of PV panels is relatively stable with only minor variability, which justifies the investment in Istanbul. Same with shading devices, which lead to a satisfactory internal rate of return under uncertainty. However, with regard to comfort we find that risks could be substantial. We find that relying completely on occupants opening and closing windows for fresh air with fan coil units maintaining the indoor temperature may lead to an insufficient supply of outdoor air for occupants and a substantial risk of overheating. Overall, the results of the analysis demonstrate that understanding risks is in some cases crucial to make an informed design decision regarding various energy saving design strategies.