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Field testing of component-level model-based fault detection methods for mixing boxes and VAV fan systems

Description: An automated fault detection and diagnosis tool for HVAC systems is being developed, based on an integrated, life-cycle, approach to commissioning and performance monitoring. The tool uses component-level HVAC equipment models implemented in the SPARK equation-based simulation environment. The models are configured using design information and component manufacturers' data and then fine-tuned to match the actual performance of the equipment by using data measured during functional tests of the sort using in commissioning. This paper presents the results of field tests of mixing box and VAV fan system models in an experimental facility and a commercial office building. The models were found to be capable of representing the performance of correctly operating mixing box and VAV fan systems and detecting several types of incorrect operation.
Date: May 16, 2002
Creator: Xu, Peng & Haves, Philip
Partner: UNT Libraries Government Documents Department

Auto-DR and Pre-cooling of Buildings at Tri-City Corporate Center

Description: Over the several past years, Lawrence Berkeley National Laboratory (LBNL) has conducted field tests for different pre-cooling strategies in different commercial buildings within California. The test results indicated that pre-cooling strategies were effective in reducing electric demand in these buildings during peak periods. This project studied how to optimize pre-cooling strategies for eleven buildings in the Tri-City Corporate Center, San Bernardino, California with the assistance of a building energy simulation tool -- the Demand Response Quick Assessment Tool (DRQAT) developed by LBNL's Demand Response Research Center funded by the California Energy Commission's Public Interest Energy Research (PIER) Program. From the simulation results of these eleven buildings, optimal pre-cooling and temperature reset strategies were developed. The study shows that after refining and calibrating initial models with measured data, the accuracy of the models can be greatly improved and the models can be used to predict load reductions for automated demand response (Auto-DR) events. This study summarizes the optimization experience of the procedure to develop and calibrate building models in DRQAT. In order to confirm the actual effect of demand response strategies, the simulation results were compared to the field test data. The results indicated that the optimal demand response strategies worked well for all buildings in the Tri-City Corporate Center. This study also compares DRQAT with other building energy simulation tools (eQUEST and BEST). The comparison indicate that eQUEST and BEST underestimate the actual demand shed of the pre-cooling strategies due to a flaw in DOE2's simulation engine for treating wall thermal mass. DRQAT is a more accurate tool in predicting thermal mass effects of DR events.
Date: November 1, 2008
Creator: Yin, Rongxin; Xu, Peng & Kiliccote, Sila
Partner: UNT Libraries Government Documents Department

Study on Auto-DR and Pre-Cooling of Commercial Buildings with Thermal Mass in California

Description: This paper discusses how to optimize pre-cooling strategies for buildings in a hot California climate zone with the Demand Response Quick Assessment Tool (DRQAT), a building energy simulation tool. This paper outlines the procedure used to develop and calibrate DRQAT simulation models, and applies this procedure to eleven field test buildings. The results of a comparison between the measured demand savings during the peak period and the savings predicted by the simulation model indicate that the predicted demand shed match well with measured data for the corresponding auto-demand response (Auto-DR) days. The study shows that the accuracy of the simulation models is greatly improved after calibrating the initial models with measured data. These improved models can be used to predict load reductions for automated demand response events. The simulation results were compared with field test data to confirm the actual effect of demand response strategies. Results indicate that the optimal demand response strategies worked well for most of the buildings tested in this hot climate zone.
Date: January 9, 2010
Creator: Yin, Rongxin; Xu, Peng; Piette, Mary Ann & Kiliccote, Sila
Partner: UNT Libraries Government Documents Department

Demand Shifting with Thermal Mass in Large Commercial Buildings in a California Hot Climate Zone

Description: The potential for using building thermal mass for load shifting and peak energy demand reduction has been demonstrated in a number of simulation, laboratory, and field studies. Previous Lawrence Berkeley National Laboratory research has demonstrated that the approach is very effective in cool and moderately warm climate conditions (California Climate Zones 2-4). However, this method had not been tested in hotter climate zones. This project studied the potential of pre-cooling the building early in the morning and increasing temperature setpoints during peak hours to reduce cooling-related demand in two typical office buildings in hotter California climates ? one in Visalia (CEC Climate Zone 13) and the other in San Bernardino (CEC Climate Zone 10). The conclusion of the work to date is that pre-cooling in hotter climates has similar potential to that seen previously in cool and moderate climates. All other factors being equal, results to date indicate that pre-cooling increases the depth (kW) and duration (kWh) of the possible demand shed of a given building. The effectiveness of night pre-cooling in typical office building under hot weather conditions is very limited. However, night pre-cooling is helpful for office buildings with an undersized HVAC system. Further work is required to duplicate the tests in other typical buildings and in other hot climate zones and prove that pre-cooling is truly effective.
Date: June 1, 2009
Creator: Xu, Peng; Yin, Rongxin; Brown, Carrie & Kim, DongEun
Partner: UNT Libraries Government Documents Department

Demand Shifting with Thermal Mass in Light and Heavy Mass Commercial Buildings

Description: The potential for utilizing building thermal mass for load shifting and peak demand reduction has been demonstrated in a number of simulation, laboratory, and field studies. This project studied the potential of pre-cooling and demand limiting in a heavy mass and a light mass building in the Bay Area of California. The conclusion of the work to date is that pre-cooling has the potential to improve the demand responsiveness of commercial buildings while maintaining acceptable comfort conditions. Results indicate that pre-cooling increases the depth (kW) and duration (kWh) of the shed capacity of a given building, all other factors being equal. Due to the time necessary for pre-cooling, it is only applicable to day-ahead demand response programs. Pre-cooling can be very effective if the building mass is relatively heavy. The effectiveness of night pre-cooling under hot weather conditions has not been tested. Further work is required to quantify and demonstrate the effectiveness of pre-cooling in different climates. Research is also needed to develop screening tools that can be used to select suitable buildings and customers, identify the most appropriate pre-cooling strategies, and estimate the benefits to the customer and the utility.
Date: May 1, 2009
Creator: Xu, Peng & Zagreus, Leah
Partner: UNT Libraries Government Documents Department

Measured energy performance of a US-China demonstrationenergy-efficient office building

Description: In July 1998, the U.S. Department of Energy (USDOE) and China's Ministry of Science of Technology (MOST) signed a Statement of Work (SOW) to collaborate on the design and construction of an energy-efficient demonstration office building and design center to be located in Beijing. The proposed 13,000 m{sup 2} (140,000 ft{sup 2}) nine-story office building would use U.S. energy-efficient materials, space-conditioning systems, controls, and design principles that were judged to be widely replicable throughout China. The SOW stated that China would contribute the land and provide for the costs of the base building, while the U.S. would be responsible for the additional (or marginal) costs associated with the package of energy efficiency and renewable energy improvements to the building. The project was finished and the building occupied in 2004. Using DOE-2 to analyze the energy performance of the as-built building, the building obtained 44 out of 69 possible points according to the Leadership in Energy and Environmental Design (LEED) rating, including the full maximum of 10 points in the energy performance section. The building achieved a LEED Gold rating, the first such LEED-rated office building in China, and is 60% more efficient than ASHRAE 90.1-1999. The utility data from the first year's operation match well the analysis results, providing that adjustments are made for unexpected changes in occupancy and operations. Compared with similarly equipped office buildings in Beijing, this demonstration building uses 60% less energy per floor area. However, compared to conventional office buildings with less equipment and window air-conditioners, the building uses slightly more energy per floor area.
Date: August 28, 2006
Creator: Xu, Peng; Huang, Joe; Jin, Ruidong & Yang, Guoxiong
Partner: UNT Libraries Government Documents Department

A Semi-Automated Functional Test Data Analysis Tool

Description: The growing interest in commissioning is creating a demand that will increasingly be met by mechanical contractors and less experienced commissioning agents. They will need tools to help them perform commissioning effectively and efficiently. The widespread availability of standardized procedures, accessible in the field, will allow commissioning to be specified with greater certainty as to what will be delivered, enhancing the acceptance and credibility of commissioning. In response, a functional test data analysis tool is being developed to analyze the data collected during functional tests for air-handling units. The functional test data analysis tool is designed to analyze test data, assess performance of the unit under test and identify the likely causes of the failure. The tool has a convenient user interface to facilitate manual entry of measurements made during a test. A graphical display shows the measured performance versus the expected performance, highlighting significant differences that indicate the unit is not able to pass the test. The tool is described as semiautomated because the measured data need to be entered manually, instead of being passed from the building control system automatically. However, the data analysis and visualization are fully automated. The tool is designed to be used by commissioning providers conducting functional tests as part of either new building commissioning or retro-commissioning, as well as building owners and operators interested in conducting routine tests periodically to check the performance of their HVAC systems.
Date: May 1, 2005
Creator: Xu, Peng; Haves, Philip & Kim, Moosung
Partner: UNT Libraries Government Documents Department

Peak demand reduction from pre-cooling with zone temperature reset in an office building

Description: The objective of this study was to demonstrate the potential for reducing peak-period electrical demand in moderate-weight commercial buildings by modifying the control of the HVAC system. An 80,000 ft{sup 2} office building with a medium-weight building structure and high window-to-wall ratio was used for a case study in which zone temperature set-points were adjusted prior to and during occupancy. HVAC performance data and zone temperatures were recorded using the building control system. Additional operative temperature sensors for selected zones and power meters for the chillers and the AHU fans were installed for the study. An energy performance baseline was constructed from data collected during normal operation. Two strategies for demand shifting using the building thermal mass were then programmed in the control system and implemented progressively over a period of one month. It was found that a simple demand limiting strategy performed well in this building. This strategy involved maintaining zone temperatures at the lower end of the comfort region during the occupied period up until 2 pm. Starting at 2 pm, the zone temperatures were allowed to float to the high end of the comfort region. With this strategy, the chiller power was reduced by 80-100% (1-2.3 W/ft{sup 2}) during normal peak hours from 2-5 pm, without causing any thermal comfort complaints. The effects on the demand from 2-5 pm of the inclusion of pre-cooling prior to occupancy are unclear.
Date: August 1, 2004
Creator: Xu, Peng; Haves, Philip; Piette, Mary Ann & Braun, James
Partner: UNT Libraries Government Documents Department

HVAC component data modeling using industry foundation classes

Description: The Industry Foundation Classes (IFC) object data model of buildings is being developed by the International Alliance for Interoperability (IAI). The aim is to support data sharing and exchange in the building and construction industry across the life-cycle of a building. This paper describes a number of aspects of a major extension of the HVAC part of the IFC data model. First is the introduction of a more generic approach for handling HVAC components. This includes type information, which corresponds to catalog data, occurrence information, which defines item-specific attributes such as location and connectivity, and performance history information, which documents the actual performance of the component instance over time. Other IFC model enhancements include an extension of the connectivity model used to specify how components forming a system can be traversed and the introduction of time-based data streams. This paper includes examples of models of particular types of HVAC components, such as boilers and actuators, with all attributes included in the definitions. The paper concludes by describing the on-going process of model testing, implementation and integration into the complete IFC model and how the model can be used by software developers to support interoperability between HVAC-oriented design and analysis tools.
Date: July 1, 2002
Creator: Bazjanac, Vladimir; Forester, James; Haves, Philip; Sucic, Darko & Xu, Peng
Partner: UNT Libraries Government Documents Department

Demand Shifting With Thermal Mass in Large Commercial Buildings:Field Tests, Simulation and Audits

Description: The principle of pre-cooling and demand limiting is to pre-cool buildings at night or in the morning during off-peak hours, storing cooling in the building thermal mass and thereby reducing cooling loads and reducing or shedding related electrical demand during the peak periods. Cost savings are achieved by reducing on-peak energy and demand charges. The potential for utilizing building thermal mass for load shifting and peak demand reduction has been demonstrated in a number of simulation, laboratory, and field studies (Braun 1990, Ruud et al. 1990, Conniff 1991, Andresen and Brandemuehl 1992, Mahajan et al. 1993, Morris et al. 1994, Keeney and Braun 1997, Becker and Paciuk 2002, Xu et al. 2003). This technology appears to have significant potential for demand reduction if applied within an overall demand response program. The primary goal associated with this research is to develop information and tools necessary to assess the viability of and, where appropriate, implement demand response programs involving building thermal mass in buildings throughout California. The project involves evaluating the technology readiness, overall demand reduction potential, and customer acceptance for different classes of buildings. This information can be used along with estimates of the impact of the strategies on energy use to design appropriate incentives for customers.
Date: September 1, 2005
Creator: Xu, Peng; Haves, Philip; Piette, Mary Ann & Zagreus, Leah
Partner: UNT Libraries Government Documents Department

Developing a next-generation community college curriculum forenergy-efficient high-performance building operations

Description: The challenges of increased technological demands in today's workplace require virtually all workers to develop higher-order cognitive skills including problem solving and systems thinking in order to be productive. Such ''habits of mind'' are viewed as particularly critical for success in the information-based workplace, which values reduced hierarchy, greater worker independence, teamwork, communications skills, non-routine problem solving, and understanding of complex systems. The need is particularly compelling in the buildings arena. To scope the problem, this paper presents the results of interviews and focus groups--conducted by Oakland California's Peralta Community College District and Lawrence Berkeley National Laboratory--in which approximately 50 industry stakeholders discussed contemporary needs for building operator education at the community college level. Numerous gaps were identified between the education today received by building operators and technicians and current workplace needs. The participants concurred that many of the problems seen today in achieving and maintaining energy savings in buildings can be traced to inadequacies in building operation and lack of awareness and knowledge about how existing systems are to be used, monitored, and maintained. Participants and others we interviewed affirmed that while these issues are addressed in various graduate-level and continuing education programs, they are virtually absent at the community college level. Based on that assessment of industry needs, we present a new curriculum and innovative simulation-based learning tool to provide technicians with skills necessary to commission and operate high-performance buildings, with particular emphasis on energy efficiency and indoor environmental quality in the context of HVAC&R equipment and control systems.
Date: May 1, 2004
Creator: Crabtree, Peter; Kyriakopedi, Nick; Mills, Evan; Haves, Philip; Otto, Roland J.; Piette, Mary Ann et al.
Partner: UNT Libraries Government Documents Department

Early evaluation of a second generation information monitoring and diagnostic system

Description: Private sector commercial office buildings are challenging environments for energy efficiency projects. This challenge is related to the complexity of business environments that involve ownership, operation, and tenant relationships. Whether it is poor quality design, inefficient operations, degradation of equipment over time, or merely the increasing use of energy by tenants and inattention from landlords, commercial office building energy use continues to increase. This research project was developed to examine the environment for building operations and identify causes of inefficient use of energy related to technical and organizational issues. This report discusses a second-generation Information Monitoring and Diagnostic System (IMDS) installed at a leased office building in Sacramento, California. The report begins with a brief summary of the IMDS research at the previous building, followed by a discussion of the building selection process, the IMDS design and installation, recent use of the IMDS, costs and benefits, and fault detection and diagnostic research using the IMDS. A web site describes the IMDS in detail (see imds.lbl.gov). The underlying principle of this research project is that high quality building performance data can help show where energy is being used and how buildings systems actually perform is an important first step toward improving building energy efficiency. The project utilizes a high-quality monitoring system that has been developed during the past decade by a partnership between LBNL and private industry. This research project has been successful in demonstrating that the IMDS is tremendously valuable to the building operators at the Sacramento site. The building operators not only accept the technology, but it has become the core of their day-to-day building control concepts. The innovative property management company, Jones Lang LaSalle, is interested in installing more sites to determine if the system could provide an economic platform for regional operations. One objective of this project ...
Date: March 25, 2002
Creator: Piette, Mary Ann; Kinney, Satkartar; Bourassa, Norman; Xu, Peng; Haves, Philip; Kinney, Kristopher et al.
Partner: UNT Libraries Government Documents Department

Automated Critical Peak Pricing Field Tests: Program Descriptionand Results

Description: California utilities have been exploring the use of critical peak prices (CPP) to help reduce needle peaks in customer end-use loads. CPP is a form of price-responsive demand response (DR). Recent experience has shown that customers have limited knowledge of how to operate their facilities in order to reduce their electricity costs under CPP (Quantum 2004). While the lack of knowledge about how to develop and implement DR control strategies is a barrier to participation in DR programs like CPP, another barrier is the lack of automation of DR systems. During 2003 and 2004, the PIER Demand Response Research Center (DRRC) conducted a series of tests of fully automated electric demand response (Auto-DR) at 18 facilities. Overall, the average of the site-specific average coincident demand reductions was 8% from a variety of building types and facilities. Many electricity customers have suggested that automation will help them institutionalize their electric demand savings and improve their overall response and DR repeatability. This report focuses on and discusses the specific results of the Automated Critical Peak Pricing (Auto-CPP, a specific type of Auto-DR) tests that took place during 2005, which build on the automated demand response (Auto-DR) research conducted through PIER and the DRRC in 2003 and 2004. The long-term goal of this project is to understand the technical opportunities of automating demand response and to remove technical and market impediments to large-scale implementation of automated demand response (Auto-DR) in buildings and industry. A second goal of this research is to understand and identify best practices for DR strategies and opportunities. The specific objectives of the Automated Critical Peak Pricing test were as follows: (1) Demonstrate how an automated notification system for critical peak pricing can be used in large commercial facilities for demand response (DR). (2) Evaluate effectiveness of such a system. ...
Date: April 6, 2006
Creator: Piette, Mary Ann; Watson, David; Motegi, Naoya; Kiliccote, Sila & Xu, Peng
Partner: UNT Libraries Government Documents Department

Assembly of 500,000 inter-specific catfish expressed sequence tags and large scale gene-associated marker development for whole genome association studies

Description: Background-Through the Community Sequencing Program, a catfish EST sequencing project was carried out through a collaboration between the catfish research community and the Department of Energy's Joint Genome Institute. Prior to this project, only a limited EST resource from catfish was available for the purpose of SNP identification. Results-A total of 438,321 quality ESTs were generated from 8 channel catfish (Ictalurus punctatus) and 4 blue catfish (Ictalurus furcatus) libraries, bringing the number of catfish ESTs to nearly 500,000. Assembly of all catfish ESTs resulted in 45,306 contigs and 66,272 singletons. Over 35percent of the unique sequences had significant similarities to known genes, allowing the identification of 14,776 unique genes in catfish. Over 300,000 putative SNPs have been identified, of which approximately 48,000 are high-quality SNPs identified from contigs with at least four sequences and the minor allele presence of at least two sequences in the contig. The EST resource should be valuable for identification of microsatellites, genome annotation, large-scale expression analysis, and comparative genome analysis. Conclusions-This project generated a large EST resource for catfish that captured the majority of the catfish transcriptome. The parallel analysis of ESTs from two closely related Ictalurid catfishes should also provide powerful means for the evaluation of ancient and recent gene duplications, and for the development of high-density microarrays in catfish. The inter- and intra-specific SNPs identified from all catfish EST dataset assembly will greatly benefit the catfish introgression breeding program and whole genome association studies.
Date: March 23, 2010
Creator: Catfish Genome Consortium
Partner: UNT Libraries Government Documents Department