Rick Diamond

Fault detection in HVAC systems using model-based feedforward control

This paper describes how a model-based feedforward control scheme can improve control performance over traditional PI(D) and detect faults in the controlled process. The scheme uses static simulation models of the system under control to generate feedforward control action, which supplements a conventional PI(D) feedback loop. The feedforward action reduces the effect of plant non-linearity on control performance and provides more consistent disturbance rejection as operating conditions change. In addition to generating feedforward control action, the models act as a reference of correct operation. Faults that occur in the system under control cause the PI(D) loop to provide a greater than normal control action to compensate for fault-induced discrepancies between the feedforward models and the controlled process. By monitoring the level of feedback compensation, faults can be detected in the controlled process. The paper presents results from testing the controller with a simulated dual-duct air-handling unit. We also discuss recent experiences of implementing the control scheme in a real building using the BACnet communication protocol.

Domestic hot water consumption in four low-income apartment buildings

We investigated domestic hot water consumption in four apartment buildings (a total of 48 units) managed by the San Francisco Public Housing Authority (PHA). In each of the buildings, we monitored system performance for 4–6 months and interviewed residents about hot water usage patterns. The shape of the measured profiles of daily domestic hot water consumption is different from that of published profiles, suggesting that cost-effective retrofits in multifamily buildings should rely on hot water use profiles in these kinds of buildings rather than those in single-family dwellings. We constructed a model of household water consumption based on reported behavior and found occupant-reported water-consuming behavior to correspond well with measured data: building differences ranged from — 19% (the model underpredicts) to 12% (the model overpredicts), and the average difference was approximately 12%. These results suggest that survey information can be used for estimating hot water usage for multifamily buildings without detailed monitoring.

Findings from a low-energy, new commercial-buildings research and demonstration project

Energy edge (EE) was a research-oriented demonstration project that began in 1985; 28 buildings were constructed to use 30% less electricity than a hypothetical simulated baseline building. Average energy savings for 18 buildings evaluated with post-occupancy tuned simulation models were less at 17%. Only six met the cost of conserved (CCE) energy of 5.6 ¢/kWh for the total package of energy-efficiency measures because the building characteristics changed from design assumptions. Forty-one percent of the individual energy-efficiency measures met the target CCE. The cost effectiveness of the measures would have been greater if the baseline had been common practice rather than the regional building code. The EE small offices use about 30–50% less energy than comparable buildings. Savings also would have been greater if commissioning was included within the program. Future projects should consider lower-cost “hands-on” evaluation techniques with annual check-ups to ensure persistence of savings.

Is Efficiency Enough? Towards a New Framework for Carbon Savingsin the California Residential Sector

The overall implementation of energy efficiency in the United States is not adequately aligned with the environmental benefits claimed for efficiency, because it does not consider absolute levels of energy use, pollutant emissions, or consumption. In some ways, promoting energy efficiency may even encourage consumption. A more effective basis for environmental policy could be achieved by recognizing the degree and nature of the synchronization between environmental objectives and efficiency. This research seeks to motivate and initiate exploration of alternative ways of defining efficiency or otherwise moderating energy use toward reaching environmental objectives, as applicable to residential electricity use in California. The report offers three main recommendations: (1) produce definitions of efficiency that better integrate absolute consumption, (2) attend to the deeper social messages of energy efficiency communications, and (3) develop a more critical perspective on benefits and limitations of energy efficiency for delivering environmental benefits. In keeping with the exploratory nature of this project, the report also identifies ten questions for further investigation.

Transforming the Energy Economy – the Role of Behavioral and Social Science

Human factors engineering can provide a unique set of concepts and methods to facilitate transforming the energy economy to less resource intensive utilization. While this has not been a traditional endeavor for the profession, new developments in technologies associated with the smart grid, and a need to understand and modify consumption patterns represent new opportunities. This panel assembles experts in behavioral science and energy analysis to discuss the various ways that the human factors and ergonomics profession can contribute to enhancing energy efficiency, conservation and greenhouse gas reduction.

A lifestyle-based scenario for US buildings: implications for energy use

Can lifestyle-based scenarios provide insight into the nature of energy use in our future buildings? Participants in a design charrette brainstormed ideas about the future of US homes and workplaces. The teams started from several descriptions of daily lifestyles, and developed specific building characteristics as the place settings for these narratives. In addition to characterizing the physical environment, the teams also identified the forces that would be influential in making these changes. Further reflection was made on the possible unintended consequences of these changes. The energy implications of these changes were characterized with respect to magnitude and direction. While acknowledging the speculative nature of the exercise, the rationale was to broaden the discussion on future energy use by looking at future scenarios in the context of everyday life.

An R&D guide and multiyear plan for improving energy use in existing commercial buildings

LBNL-56173 An R&D Guide and Multiyear Plan for Improving Energy Use in Existing Commercial Buildings R. C. Diamond Environmental Energy Technologies Division Lawrence Berkeley National Laboratory August 2004 Prepared for the U.S. Department of Energy Under Contract DE-AC03-76SF00098

Evidence-Based Background Material Underlying Guidance for Federal Agencies in Implementing Strategic Sustainability Performance Plans Implementing Sustainability: The Institutional-Behavioral Dimension

This document is part of a larger, programmatic effort to assist federal agencies in taking action and changing their institutions to achieve and maintain federal sustainability goals, while meeting their mission goals. FEMP is developing guidance for federal agency efforts to enable institutional behavior change for sustainability, and for making sustainability “business as usual.” The driving requirement for this change is Executive Order (EO) 13514, Federal Leadership in Environmental, Energy, and Economic Performance. FEMP emphasizes strategies for increasing energy efficiency and renewable energy utilization as critical components of attaining sustainability, and promotes additional non-energy action pathways contained in EO 13514. This report contributes to the larger goal by laying out the conceptual and evidentiary underpinnings of guidance to federal agencies. Conceptual frameworks focus and organize the development of guidance. We outline a series of progressively refined conceptual frameworks, including a multi-layer approach, key steps in sustainability implementation, a process view of specific approaches to institutional change, the agency Strategic Sustainability Performance Plans (SSPPs), and concepts related to context-specific rules, roles and tools for sustainability. Additionally, we tap pertinent bodies of literature in drawing eight evidence-based principles for behavior change. These principles are important foundations upon which to build in selecting strategies to effect change in organizations. Taken together, this report presents a suite of components that inform the training materials, presentations, web site, and other products that provide guidance to federal agencies.

A prototype data archive for the PIER 'thermal distribution systems in commercial buildings' project

A prototype archive for a selection of building energy data on thermal distribution systems in commercial buildings was developed and pilot tested. While the pilot demonstrated the successful development of the data archive prototype, several questions remain about the usefulness of such an archive. Specifically, questions on the audience, frequency of use, maintenance, and updating of the archive would need to be addressed before this prototype is taken to the next level.

What might U.S. homes and workplaces be like in the year 2020--and what are the implications for energy use?

Can lifestyle-based scenarios provide insight into the nature of energy use in our future buildings? Participants in a design charrette brainstormed ideas about the future of US homes and workplaces. The teams started from several descriptions of daily lifestyles, and developed specific building characteristics as the place settings for these narratives. In addition to the characterization of the physical environment, we also speculate as to the forces that would be influential in making these changes. Further reflection was made on the possible unintended consequences of these changes. The rationale for this exercise was to broaden the discussion on future energy use by looking at future scenarios in the context of everyday life.