Model based failure mode effect analysis on whole building energy performance

It is a known fact that fault in the buildings can cause as much as 30% increase in energy consumption. Thus, identifying critical failure modes affecting building energy performance is important. It can lead to actions to eliminate them, but it could as well play a role in designing a suitable monitoring and diagnostic system. Typically, expert judgment is used to guess critical faults, which leads to over instrumented, complex, and expensive building performance monitoring and diagnostic systems. In this paper, we demonstrate the application of Building performance simulation (BPS) tools to perform failure mode effect analysis and also propose a systematic process to identify and prioritize critical faults. BPS tools can play significant role in facilitating energy retrofit analysis, supporting retro-commissioning activities and act as design support tool for sensor network to be used for continuous commissioning. However, current state of the art tools do not provide ability to model and simulate faults occurring in buildings. Thus, a readily deployable and generic fault modeling capability is required in order to take advantage of BPS tools for these applications. In this paper we present a building system fault modeling library developed in TRNSYS, a process for quantifying impact of individual as well as fault couplings and demonstrate both the process and the use of the fault library on a medium sized office building. The findings show that the fault coupling can boost the effect of faults that are individually not significant, which is not intuitive.