A new control score concept for building performance assessment. (1st May 2023)

• Record Type: Journal Article
• Authors: Salsbury, Timothy I.; Rogers, Austin P.; Yoder, Tim A.; Johnson, Stephanie R.; Duan, Xiaoli
• Is Part Of: Journal of building engineering. Volume 66(2023)
• Publication Date: 2023-05-01
• Subjects: Building control score -- Control performance assessment -- Supervisory control -- Building energy use -- HVAC systems; Building -- Periodicals; 690.05
• DOI: 10.1016/j.jobe.2022.105770
• Languages: English
• ISSNs: 2352-7102

Abstract

Abstract: In buildings, performance assessment often focuses on energy use with metrics such as energy use intensity (EUI) used to benchmark performance. However, energy performance of a building is fundamentally determined by the control system and how it engages the energy-using systems. There are two aspects of control that are of particular importance: (1) the ability to regulate process variables to their setpoints; and (2) whether the setpoints are at the right levels and/or following desired profiles. Most buildings do not reach their energy efficiency potential due to deficiencies in control performance and operators do not have access to metrics that can illuminate these deficiencies. This paper addresses this problem by providing novel techniques that combine these two aspects of control performance into a single standardized score on the scale of 0–10. The concept of a standardized control score enables all systems in a building to be compared on the same scale and also for scores to be rolled up to different levels in the system and building hierarchy for system-wide analysis. The paper presents the theory for the method, describes a prototype tool for displaying scores, and presents results from application to a large building in Minneapolis. Highlights: A standardized score to characterize the performance of control loops on a scale 0-10. A dashboard display that organizes scores and consolidates them to provide device, system, building, campus, level views of performance. Results are presented from application to real buildings and operators were engaged to validate the results. The control score concept avoids the need for defining thresholds and setting alarms.