scope:

Building energy systems often consume in excess of 20% more electrical energy than was the design intent largely because of equipment performance degradation (e.g., filter or heat exchanger fouling), equipment failures, or detrimental interactions among subsystems such as cooling and then reheating of conditioned air. Identifying the root causes of efficiency losses is challenging because a gradual erosion of performance can be difficult to detect. Furthermore, diagnostic algorithm performance is limited by available fault ground truth data. An analytical framework and model-based simulation capability is desired to develop fault ground truth data that can be used to deploy robust diagnostics for building energy systems including building envelope, lighting, Heating, Ventilation and Air-conditioning (HVAC) equipment and systems, etc. Such fault simulators can also be used for fault impact analysis for risk management. An EnergyPlus/OpenStudio-based fault simulator is being developed for such purposes. EnergyPlus is a whole building simulation free program from DOE. This paper is focusing on the faults that are implemented using OpenStudio measures. These measures are created in OpenStudio Application or the Parametric Analysis Tool, which are written in Ruby scripts. These faults related measures act like add-on macro to make changes to the existing energy model to reflect faults. This fault simulator aims to simulate a variety of faults from building subcomponents and subsystems including building envelope insulation, occupancy schedule, air handler economizers, heating and cooling coils, fans, etc. The development of such a fault simulator using OpenStudio measures and testing results of fault impacts in terms of energy consumptions will be presented in this paper.