Tuesday, January 31, 2017: 9:45 AM-11:00 AM
Building Operation and Performance
Chair:
Michael Bobker, CUNY Institute for Urban Systems
Technical Committee: 7.3 Operation and Maintenance Management
CoSponsor: 1.5 Computer Applications
This session examines challenges in coordinating data extracted from building automation systems with predictions from building energy models. With BEM increasingly informing design decisions, comparison to post-construction performance at the system level becomes key to troubleshooting and tuning. Discrepancies often first noted in whole-building energy use must be traced back to system level sources. Such comparison between BAS and BEM data is hindered by inconsistencies in data organization, naming, grouping and parameters. This issue is examined as a use-case for ASHRAE Guideline 20-2010, Documenting HVAC&R Work Processes and Data Exchange Requirements.
1 Real-Time Energy Simulation for Whole Building Performance Monitoring
A model-based real-time whole building energy monitoring and diagnostics is presented. The proposed system continuously acquires performance measurements of HVAC, lighting and plug load usage from the Building Energy Management System (BEMS) and compares these measurements in real-time to a calibrated reference EnergyPlus model. The structure of categories for extracted data and model outputs is described, along with discussion of adjustments necessary to EnergyPlus reporting and set up of BEMS trending. A proof of concept demonstration is presented.
2 BEM-BAS Data Exchange
Model-based performance monitoring requires comparison of data generated from two distinct kinds of system, the Building Energy Model (BEM) and the Building Automation System (BAS). The HVAC design process at present places no requirement for interoperability between them. In the performance monitoring use-case, they will no longer be stand-alone elements. ASHRAE Guideline 20-2010 Documenting HVAC&R Work Processes for Data Exchange Requirements provides a use-case approach to information issues. The Guideline 20 process is applied to BEM-BAS data comparisons to better understand where incompatibilities lie. Examples are developed such as equipment naming, operating profiles, energy and physical parameters.
3 BIM-Based Energy Model Calibration for Evaluating Building Retrofit Opportunities
Recent progress in BIM to BEM for energy analysis has proven to be effective for early design analysis and parametric evaluations of design options. Several cloud-based simulation strategies have been developed for auto-tuning and model calibration using utility billing data. This presentation summarizes an approach integrating BIM to BIM and cloud-based parametric simulations for developing calibrated energy models from BIM using site specific weather data. It is possible to use the calibrated model in conjunction with parametric design analysis for evaluating retrofit opportunities. Examples are presented to dynamically evaluate retrofit options without performing additional simulations.