@article {32192, title = {Culture, conformity, and carbon? A multi-country analysis of heating and cooling practices in office buildings}, journal = {Energy Research \& Social Science}, volume = {61}, year = {2020}, month = {Jan-03-2020}, pages = {101344}, abstract = {

This study investigates human-building interaction in office spaces across multiple countries including Brazil, Italy, Poland, Switzerland, the United States, and Taiwan. We analyze social-psychological, contextual, and demographic factors to explain cross-country differences in adaptive thermal actions (i.e. cooling and heating behaviors) and conformity to the norms of sharing indoor environmental control features, an indicator of energy consumption. Specifically, personal adjustments such as putting on extra clothes are generally preferred over technological solutions such as adjusting thermostats in reaction to thermal discomfort. Social-psychological factors including attitudes, perceived behavioral control, injunctive norms, and perceived impact of indoor environmental quality on work productivity influence occupants{\textquoteright} intention to conform to the norms of sharing environmental control features. Lastly, accessibility to environmental control features, office type, gender, and age are also important factors. These findings demonstrate the roles of social-psychological and certain contextual factors in occupants{\textquoteright}
interactions with building design as well as their behavior of sharing environmental control features, both of which significantly influence building energy consumption, and thus, broader decarbonization.

}, issn = {22146296}, doi = {10.1016/j.erss.2019.101344}, author = {Chen, Chien-fei and Tianzhen Hong and de Rubens, Gerardo Zarazua and Yilmaz, Selin and Bandurski, Karol and B{\'e}lafi, Zs{\'o}fia Deme and De Simone, Marilena and Bavaresco, Mateus Vin{\'\i}cius and Wang, Yu and Liu, Pei-ling and Barthelmes, Verena M. and Adams, Jacqueline and D{\textquoteright}Oca, Simona and Przybylski, {\L}ukasz} } @conference {31839, title = {Comparison of MPC Formulations for Building Control under Commercial Time-of-Use Tariffs}, booktitle = {IEEE PowerTech Milan 2019}, year = {2019}, month = {2019}, abstract = {

Most medium and large commercial buildings in\ the U.S. are subject to complex electricity tariffs that combine\ both Time-of-Use (TOU) energy and demand charges. This study\ analyses the performances of different economic Model Predictive\ Control (MPC) formulations, from the standpoints of monthly bill\ reduction, load shifting, and peak demand reduction. Simulations\ are performed on many simplified commercial building models,\ with multiple TOU demand charges, and under various summer\ conditions. Results show that compared to energy-only MPC, the\ traditional method for dealing with demand charges significantly
reduces peak demand and owner bill, however, highlight a lack\ of load shifting capability. A proposed incremental approach
is presented, which better balances the bill components in the\ objective function. In the case study presented, this method
can improve monthly bill savings and increase load shifting\ during demand response events, while keeping a similarly low
peak demand, compared to traditional MPC methods taking into\ account demand charges.

}, keywords = {commercial building, demand charge, Model predictive control (MPC), peak demand, time-of-use tarrif}, author = {Olivier Van Cutsem and Maher Kayal and David Blum and Marco Pritoni} } @article {31362, title = {Practical factors of envelope model setup and their effects on the performance of model predictive control for building heating, ventilating, and air conditioning systems}, journal = {Applied Energy}, volume = {236}, year = {2019}, month = {02/2019}, pages = {410 - 425}, abstract = {

Model predictive control (MPC) for buildings is attracting significant attention in research and industry due to its potential to address a number of challenges facing the building industry, including energy cost reduction, grid integration, and occupant connectivity. However, the strategy has not yet been implemented at any scale, largely due to the significant effort required to configure and calibrate the model used in the MPC controller. While many studies have focused on methods to expedite model configuration and improve model accuracy, few have studied the impact a wide range of factors have on the accuracy of the resulting model. In addition, few have continued on to analyze these factors{\textquoteright} impact on MPC controller performance in terms of final operating costs. Therefore, this study first identifies the practical factors affecting model setup, specifically focusing on the thermal envelope. The seven that are identified are building design, model structure, model order, data set, data quality, identification algorithm and initial guesses, and software tool-chain. Then, through a large number of trials, it analyzes each factor{\textquoteright}s influence on model accuracy, focusing on grey-box models for a single zone building envelope. Finally, this study implements a subset of the models identified with these factor variations in heating, ventilating, and air conditioning MPC controllers, and tests them in simulation of a representative case that aims to optimally cool a single-zone building with time-varying electricity prices. It is found that a difference of up to 20\% in cooling cost for the cases studied can occur between the best performing model and the worst performing model. The primary factors attributing to this were model structure and initial parameter guesses during parameter estimation of the model.

}, keywords = {building simulation, hvac, Model predictive control, System identification}, issn = {03062619}, doi = {10.1016/j.apenergy.2018.11.093}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0306261918318099https://api.elsevier.com/content/article/PII:S0306261918318099?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0306261918318099?httpAccept=text/plain}, author = {David Blum and K. Arendt and Lisa Rivalin and Mary Ann Piette and Michael Wetter and C.T. Veje} } @conference {31980, title = {Prototyping the BOPTEST Framework for Simulation-Based Testing of Advanced Control Strategies in Buildings}, booktitle = {IBPSA Building Simulation 2019}, year = {2019}, address = {Rome, Italy}, abstract = {

Advanced control strategies are becoming increasingly necessary in buildings in order to meet and balance requirements for energy efficiency, demand flexibility, and occupant comfort. Additional development and widespread adoption of emerging control strategies, however, ultimately require low implementation costs to reduce payback period and verified performance to gain control vendor, building owner, and operator trust. This is difficult in an already first-cost driven and risk-averse industry. Recent innovations in building simulation can significantly aid in meeting these requirements and spurring innovation at early stages of development by evaluating performance, comparing state-of-the-art to new strategies, providing installation experience, and testing controller implementations. This paper presents the development of a simulation framework consisting of test cases and software platform for the testing of advanced control strategies (BOPTEST - Building Optimization Performance Test). The objectives and requirements of the framework, components of a test case, and proposed software platform architecture are described, and the framework is demonstrated with a prototype implementation and example test case.

}, keywords = {benchmarking, building simulation, Model predictive control, software development}, author = {David Blum and Filip Jorissen and Sen Huang and Yan Chen and Javier Arroyo and Kyle Benne and Yanfei Li and Valentin Gavan and Lisa Rivalin and Lieve Helsen and Draguna Vrabie and Michael Wetter and Marina Sofos} } @article {30727, title = {Bidirectional low temperature district energy systems with agent-based control: Performance comparison and operation optimization}, journal = {Applied Energy}, volume = {209}, year = {2018}, doi = {10.1016/j.apenergy.2017.10.072}, author = {Felix Bunning and Michael Wetter and Marcus Fuchs and Dirk Muller} } @article {31307, title = {A critical review on questionnaire surveys in the field of energy-related occupant behaviour}, journal = {Energy Efficiency}, year = {2018}, month = {07/2018}, pages = {1-21}, abstract = {

Occupants perform various actions to satisfy their physical and non-physical needs in buildings. These actions greatly affect building operations and thus energy use. Clearly understanding and accurately modelling occupant behaviour in buildings are crucial to guide energy-efficient building design and operation, and to reduce the gap between design and actual energy performance of buildings. To study and understand occupant behaviour, a cross-sectional questionnaire survey is one of the most useful tools to gain insights on general behaviour patterns and drivers, and to find connections between human, social and local comfort parameters. In this study, 33 projects were reviewed from the energy-related occupant behaviour research literature that employed cross-sectional surveys or interviews for data collection from the perspective of findings, limitations and methodological challenges. This research shows that future surveys are needed to bridge the gaps in literature but they would need to encompass a multidisciplinary approach to do so as until now only environmental and engineering factors were considered in these studies. Insights from social practice theories and techniques must be acquired to deploy robust and unbiased questionnaire results, which will provide new, more comprehensive knowledge in the field, and therefore occupant behaviour could be better understood and represented in building performance simulation to support design and operation of low or net-zero energy buildings.

}, keywords = {behaviour modeling, energy efficiency, Energy use in buildings, occupant behavior, questionnaire survey}, issn = {1570-646X}, doi = {10.1007/s12053-018-9711-z}, url = {http://link.springer.com/10.1007/s12053-018-9711-zhttp://link.springer.com/content/pdf/10.1007/s12053-018-9711-z.pdfhttp://link.springer.com/content/pdf/10.1007/s12053-018-9711-z.pdfhttp://link.springer.com/article/10.1007/s12053-018-9711-z/fulltext.html}, author = {Zsofia Belafi and Tianzhen Hong and Andras Reith} } @article {30484, title = {Human-building interaction at work: Findings from an interdisciplinary cross-country survey in Italy}, journal = {Building and Environment}, volume = {132}, year = {2018}, abstract = {

This study presents results from an interdisciplinary survey assessing contextual and behavioral factors driving occupants{\textquoteright} interaction with building and systems in offices located across three different Mediterranean climates in Turin (Northern), Perugia (Central), and Rende (Southern) Italy. The survey instrument is grounded in an interdisciplinary framework that bridges the gap between building physics and social science environments on the energy- and comfort-related human-building interaction in the workspace. Outcomes of the survey questionnaire provide insights into four key learning objectives: (1) individual occupant{\textquoteright}s motivational drivers regarding interaction with shared building environmental controls (such as adjustable thermostats, operable windows, blinds and shades, and artificial lighting), (2) group dynamics such as perceived social norms, attitudes, and intention to share controls, (3) occupant perception of the ease of use and knowledge of how to operate control systems, and (4) occupant-perceived comfort, satisfaction, and productivity. This study attempts to identify climatic, cultural, and socio-demographic influencing factors, as well as to establish the validity of the survey instrument and robustness of outcomes for future studies. Also, the paper aims at illustrating why and how social science insights can bring innovative knowledge into the adoption of building technologies in shared contexts, thus enhancing perceived environmental satisfaction and effectiveness of personal indoor climate control in office settings and impacting office workers{\textquoteright} productivity and reduced operational energy costs.

}, keywords = {Human-building interaction, indoor environmental comfort, interdisciplinary framework, occupant behavior, office buildings, questionnaire survey}, doi = {10.1016/j.buildenv.2018.01.039}, author = {Simona D{\textquoteright}Oca and Anna Laura Pisello and Marilena De Simone and Verena M. Barthelmes and Tianzhen Hong and Stefano P. Corgnati} } @article {30489, title = {A Library of Building Occupant Behaviour Models Represented in a Standardised Schema}, journal = {Energy Efficiency}, year = {2018}, abstract = {

Over the past four decades, a substantial body of literature has explored the impacts of occupant behaviour (OB) on building technologies, operation, and energy consumption. A large number of data-driven behavioural models have been developed based on field data. These models lack standardisation and consistency, leading to difficulties in applications and comparison. To address this problem, an ontology was developed using the drivers-needs-actions-systems (DNAS) framework. Recent work has been carried out to implement the theoretical DNAS framework into an eXtensible Markup Language (XML) schema, titled {\textquoteleft}occupant behaviour XML{\textquoteright} (obXML) which is a practical implementation of OB models that can be integrated into building performance simulation (BPS) programs. This paper presents a newly developed library of OB models represented in the standardised obXML schema format. This library provides ready-to-use examples for BPS users to employ more accurate occupant representation in their energy models. The library, which contains an initial effort of 52 OB models, was made publicly available for the BPS community. As part of the library development process, limitations of the obXML schema were identified and addressed, and future improvements were proposed. Authors hope that by compiling this library building, energy modellers from all over the world can enhance their BPS models by integrating more accurate and robust OB patterns.

}, keywords = {building performance simulation, obXML, Occupant Behaviour, occupant behaviour model, XML schema}, doi = {10.1007/s12053-018-9658-0}, author = {Zsofia Belafi and Tianzhen Hong and Andras Reith} } @conference {31355, title = {When Data Analytics Meet Site Operation: Benefits and Challenges}, booktitle = {2018 ACEEE Summer Study on Energy Efficiency in Buildings}, year = {2018}, month = {08/2018}, abstract = {

Demand for using data analytics for energy management in buildings is rising. Such analytics are required for advanced measurement and verification, commissioning, automated fault-detection and diagnosis, and optimal control. While novel analytics algorithms continue to be developed, bottlenecks and challenges arise when deploying them for demonstration, for a number of reasons that do not necessarily have to do with the algorithms themselves. It is important for developers of new technologies to be aware of the challenges and potential solutions during demonstration. Therefore, this paper describes a recent deployment of an automated, physical model-based, FDD and optimal control tool, highlighting its design and as-operated benefits that the tool provides. Furthermore, the paper presents challenges faced during deployment and testing along with solutions used to overcome these challenges. The challenges have been grouped into four categories: Data Management, Physical Model Development and Integration, Software Development and Deployment, and Operator Use. The paper concludes by discussing how challenges with this project generalize to common cases, how they could compare to other projects in their severity, and how they may be addressed.

}, author = {David Blum and Guanjing Lin and Michael Spears and Janie Page and Jessica Granderson} } @article {30728, title = {Dynamic equation-based thermo-hydraulic pipe model for district heating and cooling systems}, journal = {Energy Conversion and Management}, volume = {151}, year = {2017}, abstract = {

Simulation and optimisation of district heating and cooling networks requires efficient and realistic models of the individual network elements in order to correctly represent heat losses or gains, temperature propagation and pressure drops. Due to more recent thermal networks incorporating meshing decentralised heat and cold sources, the system often has to deal with variable temperatures and mass flow rates, with flow reversal occurring more frequently. This paper presents the mathematical derivation and software implementation in Modelica of a thermo-hydraulic model for thermal networks that meets the above requirements and compares it to both experimental data and a commonly used model. Good correspondence between experimental data from a controlled test set-up and simulations using the presented model was found. Compared to measurement data from a real district heating network, the simulation results led to a larger error than in the controlled test set-up, but the general trend is still approximated closely and the model yields results similar to a pipe model from the Modelica Standard Library. However, the presented model simulates 1.7 (for low number of volumes) to 68 (for highly discretized pipes) times faster than a conventional model for a realistic test case. A working implementation of the presented model is made openly available within the IBPSA Modelica Library. The model is robust in the sense that grid size and time step do not need to be adapted to the flow rate, as is the case in finite volume models.

}, doi = {10.1016/j.enconman.2017.08.072}, author = {Brahm van der Heijde and Marcus Fuchs and Carles Ribas Tugores and Gerald Schweiger and Kevin Sartor and Daniele Basciotti and Dirk Muller and Christoph Nytsch-Geusen and Michael Wetter and Lieve Helsen} } @article {62077, title = {Energy saving potential of a two-pipe system for simultaneous heating and cooling of office buildings}, journal = {Energy and Buildings}, volume = {134}, year = {2017}, month = {01/2017}, pages = {234 - 247}, abstract = {

This paper analyzes the performance of a novel two-pipe system that operates one water loop to simultaneously provide space heating and cooling with a water supply temperature of around 22 {\textdegree}C. To analyze the energy performance of the system, a simulation-based research was conducted. The two-pipe system was modelled using the equation-based Modelica modeling language in Dymola. A typical office building model was considered as the case study. Simulations were run for two construction sets of the building envelope and two conditions related to inter-zone air flows. To calculate energy savings, a conventional four-pipe system was modelled and used for comparison. The conventional system presented two separated water loops for heating and cooling with supply temperatures of 45 {\textdegree}C and 14 {\textdegree}C, respectively. Simulation results showed that the two-pipe system was able to use less energy than the four-pipe system thanks to three effects: useful heat transfer from warm to cold zones, higher free cooling potential and higher efficiency of the heat pump. In particular, the two-pipe system used approximately between 12\% and 18\% less total annual primary energy than the four-pipe system, depending on the simulation case considered.

}, keywords = {active beams, energy saving, HVAC systems, low-exergy, modelica, simulation}, issn = {03787788}, doi = {10.1016/j.enbuild.2016.10.051}, author = {Alessandro Maccarini and Michael Wetter and Alireza Afshari and Goran Hultmark and Niels Bergsoe and Anders Vorre} } @conference {31830, title = {MPCPy: An Open-Source Software Platform for Model Predictive Control in Buildings}, booktitle = {Proceedings of the 15th IBPSA Conference: Building Simulation 2017}, year = {2017}, month = {08/2017}, address = {San Francisco}, abstract = {

Within the last decade, needs for building control systems that reduce cost, energy, or peak demand, and that facilitate building-grid integration, district-energy system optimization, and occupant interaction, while maintaining thermal comfort and indoor air quality, have come about.\  Current PID and schedule-based control systems are not capable of fulfilling these needs, while Model Predictive Control (MPC) could.\  Despite the critical role MPC-enabled buildings can play in future energy infrastructures, widespread adoption of MPC within the building industry has yet to occur.\  To address barriers associated with system setup and configuration, this paper introduces an open-source software platform that emphasizes use of self-tuning adaptive models, usability by non-experts of MPC, and a flexible architecture that enables application across projects.

}, keywords = {Model predictive control (MPC)}, url = {http://www.ibpsa.org/proceedings/BS2017/BS2017_351.pdf}, author = {David Blum and Michael Wetter} } @article {30029, title = {Occupant behavior models: A critical review of implementation and representation approaches in building performance simulation programs}, year = {2017}, abstract = {

Occupant behavior (OB) in buildings is a leading factor influencing energy use in buildings. Quantifying this influence requires the integration of OB models with building performance simulation (BPS). This study reviews approaches to representing and implementing OB models in today{\textquoteright}s popular BPS programs, and discusses weaknesses and strengths of these approaches and key issues in integrating of OB models with BPS programs. Two key findings are: (1) a common data model is needed to standardize the representation of OB models, enabling their flexibility and exchange among BPS programs and user applications; the data model can be implemented using a standard syntax (e.g., in the form of XML schema), and (2) a modular software implementation of OB models, such as functional mock-up units for co-simulation, adopting the common data model, has advantages in providing a robust and interoperable integration with multiple BPS programs. Such common OB model representation and implementation approaches help standardize the input structures of OB models, enable collaborative development of a shared library of OB models, and allow for rapid and widespread integration of OB models with BPS programs to improve the simulation of occupant behavior and quantification of their impact on building performance.

}, keywords = {Behavior Modeling, building performance simulation, co-simulation, data model, occupant behavior}, author = {Tianzhen Hong and Yixing Chen and Zsofia Belafi and Simona D{\textquoteright}Oca} } @article {29854, title = {Small and Medium Building Efficiency Toolkit and Community Demonstration Program}, year = {2017}, month = {03/2017}, abstract = {

Small commercial buildings in the United States consume 47 percent of all primary energy consumed in the building sector. Retrofitting small and medium commercial buildings may pose a steep challenge for owners, as many lack the expertise and resources to identify and evaluate cost-effective energy retrofit strategies. To address this problem, this project developed the Commercial Building Energy Saver (CBES), an energy retrofit analysis toolkit that calculates the energy use of a building, identifies and evaluates retrofit measures based on energy savings, energy cost savings, and payback. The CBES Toolkit includes a web app for end users and the CBES Application Programming Interface for integrating CBES with other energy software tools. The toolkit provides a rich feature set, including the following:

  1. Energy Benchmarking providing an Energy Star score
  2. Load Shape Analysis to identify potential building operation improvements
  3. Preliminary Retrofit Analysis which uses a custom developed pre-simulated database
  4. Detailed Retrofit Analysis which utilizes real time EnergyPlus simulations

In a parallel effort the project team developed technologies to measure outdoor airflow rate; commercialization and use would avoid both excess energy use from over ventilation and poor indoor air quality resulting from under ventilation.

If CBES is adopted by California{\textquoteright}s statewide small office and retail buildings, by 2030 the state can anticipate 1,587 gigawatt hours of electricity savings, 356 megawatts of non-coincident peak demand savings, 30.2 megatherms of natural gas savings, $227 million of energy-related cost savings, and reduction of emissions by 757,866 metric tons of carbon dioxide equivalent. In addition, consultant costs will be reduced in the retrofit analysis process.

CBES contributes to the energy savings retrofit field by enabling a straightforward and uncomplicated decision-making process for small and medium business owners and leveraging different levels of assessment to match user background, preference, and data availability.

}, keywords = {CBES, commercial buildings, energy efficiency, energy modeling, energy savings, indoor air quality, indoor environmental quality, outdoor air measurement technology, outdoor airflow intake rate, retrofit, ventilation rate}, doi = {10.7941/S93P70}, author = {Mary Ann Piette and Tianzhen Hong and William J. Fisk and Norman Bourassa and Wanyu R. Chan and Yixing Chen and H.Y. Iris Cheung and Toshifumi Hotchi and Margarita Kloss and Sang Hoon Lee and Phillip N. Price and Oren Schetrit and Kaiyu Sun and Sarah C. Taylor-Lange and Rongpeng Zhang} } @article {30305, title = {Smart Building Management vs. Intuitive Human Control {\textemdash} Lessons learnt from an office building in Hungary}, journal = {Building Simulation}, volume = {10}, year = {2017}, month = {12/2017}, pages = {811-828}, abstract = {

Smart building management and control are adopted nowadays to achieve zero-net energy use in buildings. However, without considering the human dimension, technologies alone do not necessarily guarantee high performance in buildings. An office building was designed and built according to state-of-the-art design and energy management principles in 2008. Despite the expectations of high performance, the owner was facing high utility bills and low user comfort in the building located in Budapest, Hungary. The objective of the project was to evaluate the energy performance and comfort indices of the building, to identify the causes of malfunction and to elaborate a comprehensive energy concept. Firstly, current building conditions and operation parameters were evaluated. Our investigation found that the state-of-the-art building management system was in good conditions but it was operated by building operators and occupants who are not aware of the building management practice. The energy consumption patterns of the building were simulated with energy modelling software. The baseline model was calibrated to annual measured energy consumption, using actual occupant behaviour and presence, based on results of self-reported surveys, occupancy sensors and fan-coil usage data. Realistic occupant behaviour models can capture diversity of occupant behaviour and better represent the real energy use of the building. This way our findings and the effect of our proposed improvements could be more reliable. As part of our final comprehensive energy concept, we proposed intervention measures that would increase indoor thermal comfort and decrease energy consumption of the building. A parametric study was carried out to evaluate and quantify energy, comfort and return on investment of each measure. It was found that in the best case the building could save 23\% of annual energy use. Future work includes the follow-up of: occupant reactions to intervention measures, the realized energy savings, the measurement of occupant satisfaction and behavioural changes.

}, keywords = {building operation, building performance simulation, case study, Occupant Behaviour, optimization}, issn = {Print 1996-3599; Online 1996-8744}, doi = {10.1007/s12273-017-0361-4}, author = {Zsofia Belafi and Tianzhen Hong and Andras Reith} } @article {29896, title = {Synthesizing building physics with social psychology: An interdisciplinary framework for context and occupant behavior in office buildings}, year = {2017}, abstract = {

This study introduces an interdisciplinary framework for investigating building-user interaction in office spaces. The framework is a synthesis of theories from building physics and social psychology including social cognitive theory, the theory of planned behavior, and the drivers-needs-actions-systems ontology for energy-related behaviors. The goal of the research framework is to investigate the effects of various behavioral adaptations and building controls (i.e., adjusting thermostats, operating windows, blinds and shades, and switching on/off artificial lights) to determine impacts on occupant comfort and energy-related operational costs in the office environment. This study attempts to expand state-of-the-art understanding of: (1) the environmental, personal, and behavioral drivers motivating occupants to interact with building control systems across four seasons, (2) how occupants{\textquoteright} intention to share controls is influenced by social-psychological variables such as attitudes, subjective norms, and perceived behavioral control in group negotiation dynamic, (3) the perceived ease of usage and knowledge of building technologies, and (4) perceived satisfaction and productivity. To ground the validation of the theoretical framework in diverse office settings and contexts at the international scale, an online survey was designed to collect cross-country responses from office occupants among 14 universities and research centers within the United States, Europe, China, and Australia.

}, author = {Simona D{\textquoteright}Oca and Chien-Fen Chen and Tianzhen Hong and Zsofia Belafi} } @article {60342, title = {Equation-based languages {\textendash} A new paradigm for building energy modeling, simulation and optimization}, journal = {Energy and Buildings}, volume = {117}, year = {2015}, month = {04/2016}, pages = {290-300}, abstract = {

Most of the state-of-the-art building simulation programs implement models in imperative programming languages. This complicates modeling and excludes the use of certain efficient methods for simulation and optimization. In contrast, equation-based modeling languages declare relations among variables, thereby allowing the use of computer algebra to enable much simpler schematic modeling and to generate efficient code for simulation and optimization.

We contrast the two approaches in this paper. We explain how such manipulations support new use cases. In the first of two examples, we couple models of the electrical grid, multiple buildings, HVAC systems and controllers to test a controller that adjusts building room temperatures and PV inverter reactive power to maintain power quality. In the second example, we contrast the computing time for solving an optimal control problem for a room-level model predictive controller with and without symbolic manipulations. Exploiting the equation-based language led to 2200 times faster solution.

}, keywords = {Equation-based modeling, modelica, Multi-physics simulation, Optimal control, smart grid}, doi = {10.1016/j.enbuild.2015.10.017}, author = {Michael Wetter and Marco Bonvini and Thierry Stephane Nouidui} } @article {59965, title = {Comparison of Building Energy Use Data Between the United States and China}, journal = {Energy and Buildings}, volume = {78}, year = {2014}, month = {08/2014}, pages = {165-175}, abstract = {

Buildings in the United States and China consumed 41\% and 28\% of the total primary energy in 2011, respectively. Good energy data are the cornerstone to understanding building energy performance and supporting research, design, operation, and policy making for low energy buildings. This paper presents initial outcomes from a joint research project under the U.S.{\textendash}China Clean Energy Research Center for Building Energy Efficiency. The goal is to decode the driving forces behind the discrepancy of building energy use between the two countries; identify gaps and deficiencies of current building energy monitoring, data collection, and analysis; and create knowledge and tools to collect and analyze good building energy data to provide valuable and actionable information for key stakeholders. This paper first reviews and compares several popular existing building energy monitoring systems in both countries. Next a standard energy data model is presented. A detailed, measured building energy data comparison was conducted for a few office buildings in both countries. Finally issues of data collection, quality, sharing, and analysis methods are discussed. It was found that buildings in both countries performed very differently, had potential for deep energy retrofit, but that different efficiency measures should apply.

}, keywords = {buildings, comparison, data analysis, data model, Energy benchmarking, energy monitoring system, energy use, retrofit}, doi = {10.1016/j.enbuild.2014.04.031}, author = {Jianjun Xia and Tianzhen Hong and Qi Shen and Wei Feng and Le Yang and Piljae Im and Alison Lu and Mahabir Bhandari} } @article {59968, title = {Building Energy Monitoring and Analysis}, year = {2013}, month = {06/2013}, abstract = {

U.S. and China are the world{\textquoteright}s top two economics. Together they consumed one-third of the world{\textquoteright}s primary energy. It is an unprecedented opportunity and challenge for governments, researchers and industries in both countries to join together to address energy issues and global climate change. Such joint collaboration has huge potential in creating new jobs in energy technologies and services.

Buildings in the US and China consumed about 40\% and 25\% of the primary energy in both countries in 2010 respectively. Worldwide, the building sector is the largest contributor to the greenhouse gas emission. Better understanding and improving the energy performance of buildings is a critical step towards sustainable development and mitigation of global climate change.

This project aimed to develop a standard methodology for building energy data definition, collection, presentation, and analysis; apply the developed methods to a standardized energy monitoring platform, including hardware and software, to collect and analyze building energy use data; and compile offline statistical data and online real-time data in both countries for fully understanding the current status of building energy use. This helps decode the driving forces behind the discrepancy of building energy use between the two countries; identify gaps and deficiencies of current building energy monitoring, data collection, and analysis; and create knowledge and tools to collect and analyze good building energy data to provide valuable and actionable information for key stakeholders.

Key research findings were summarized as follows:

The research outputs from the project can help better understand energy performance of buildings, improve building operations to reduce energy waste and increase efficiency, identify retrofit opportunities for existing buildings, and provide guideline to improve the design of new buildings. The standardized energy monitoring and analysis platform as well as the collected real building data can also be used for other CERC projects that need building energy measurements, and be further linked to building energy benchmarking and rating/labeling systems.

}, author = {Tianzhen Hong and Wei Feng and Alison Lu and Jianjun Xia and Le Yang and Qi Shen and Piljae Im and Mahabir Bhandari} } @article {3443, title = {Transforming BIM to BEM: Generation of Building Geometry for the NASA Ames Sustainability Base BIM}, year = {2013}, month = {01/2013}, author = {James O{\textquoteright}Donnell and Tobias Maile and Cody Rose and Natasa Mrazovic and Elmer Morrissey and Cynthia Regnier and Kristen Parrish and Vladimir Bazjanac} } @conference {57409, title = {Application of a stochastic window use model in EnergyPlus}, booktitle = {SimBuild 2012, 5th National Conference of IBPSA-USA, August 1-3, 2012}, year = {2012}, month = {08/2012}, address = {Madison, WI}, abstract = {

Natural ventilation, used appropriately, has the potential to provide both significant HVAC energy savings, and improvements in occupant satisfaction.

Central to the development of natural ventilation models is the need to accurately represent the behavior of building occupants. The work covered in this paper describes a method of implementing a stochastic window model in EnergyPlus. Simulated window use data from three stochastic window opening models was then compared to measured window opening behavior, collected in a naturally-ventilated office in California. Recommendations regarding the selection of stochastic window use models, and their implementation in EnergyPlus, are presented.

}, url = {https://escholarship.org/uc/item/2gm7r783}, author = {Spencer M. Dutton and Hui Zhang and Yongchao Zhai and Edward A. Arens and Youness Bennani Smires and Samuel L. Brunswick and Kyle S. Konis and Philip Haves} } @conference {3444, title = {The Energy Saving Potential of Membrane-Based Enthalpy Recovery in Vav Systems for Commercial Office Buildings}, booktitle = {SimBuild 2012 IBPSA Conference}, year = {2012}, abstract = {

A design tool to evaluate the heat and mass transfer effectiveness and pressure drop of a membrane-based enthalpy exchanger was developed and then used to optimize the configuration of an enthalpy exchanger for minimum pressure drop and maximum heat recovery effectiveness. Simulation was used in a parametric study to investigate the energy saving potential of the enthalpy recovery system. The case without energy recovery and air side economizer was used as a baseline. Two comparison cases for the implementation of enthalpy recovery with and without air side economizer were simulated in EnergyPlus. A case using a desiccant wheel for energy recovery was also investigated for comparison purposes. The simulation results show significant energy saving benefits from applying a low pressure drop, high effectiveness enthalpy exchanger in two US cities representing a range of humid climates. The sensitivity of the energy savings potential to pressure drop and heat and mass transfer effectivenesses is also presented.

}, author = {Liping Wang and Philip Haves and John Breshears} } @conference {3407, title = {The Energy Saving Potential of Membrane-Based Enthalpy Recovery in VAV System for Commercial Office Buildings}, booktitle = {SimBuild 2012}, year = {2012}, month = {08/2012}, address = {Madison, Wisconsin}, author = {Liping Wang and Philip Haves and John Breshears} } @article {2591, title = {A framework for simulation-based real-time whole building performance assessment}, journal = {Building and Environment}, volume = {54}, year = {2012}, month = {08/2012}, pages = {100-108}, chapter = {100}, abstract = {

Most commercial buildings do not perform as well in practice as intended by the design and their performances often deteriorate over time. Reasons include faulty construction, malfunctioning equipment, incorrectly configured control systems and inappropriate operating procedures. One approach to addressing this problems is to compare the predictions of an energy simulation model of the building to the measured performance and analyze significant differences to infer the presence and location of faults. This paper presents a framework that allows a comparison of building actual performance and expected performance in real time. The realization of the framework utilized the EnergyPlus, the Building Controls Virtual Test Bed (BCVTB) and the Energy Management and Control System (EMCS) was developed. An EnergyPlus model that represents expected performance of a building runs in real time and reports the predicted building performance at each time step. The BCVTB is used as the software platform to acquire relevant inputs from the EMCS through a BACnet interface and send them to the EnergyPlus and to a database for archiving. A proof-of-concept demonstration is also presented.

}, keywords = {building controls virtual test bed, building performance, energy modeling, energyplus, real-time building simulation}, issn = {0360-1323}, author = {Xiufeng Pang and Michael Wetter and Prajesh Bhattacharya and Philip Haves} } @conference {3442, title = {An Improved Simple Chilled Water Cooling Coil Model}, booktitle = {SimBuild 2012 IBPSA Conference}, year = {2012}, month = {08/2012}, abstract = {

The accurate prediction of cooling and dehumidification coil performance is important in model-based fault detection and in the prediction of HVAC system energy consumption for support of both design and operations. It is frequently desirable to use a simple cooling coil model that does not require detailed specification of coil geometry and material properties. The approach adopted is to match the overall UA of the coil to the rating conditions and to estimate the air-side and water-side components of the UA using correlations developed by Holmes (1982). This approach requires some geometrical information about the coil and the paper investigates the sensitivity of the overall performance prediction to uncertainties in this information, including assuming a fixed ratio of air-side to water-side UA at the rating condition. Finally, simulation results from different coil models are compared, and experimental data are used to validate the improved cooling coil model.

}, author = {Liping Wang and Philip Haves and Walter F. Buhl} } @conference {3180, title = {Mapping Hvac Systems for Simulation In EnergyPlus}, booktitle = {SimBuild 2012 IBPSA Conference}, year = {2012}, month = {07/2012}, address = {Madison, WI, USA}, abstract = {

For building energy simulation tools to be accessible to designers, tool interfaces should present a conventional view of HVAC systems to the user, and then map this view to the internal data model used in the tool. The paper outlines a process that enables design engineers to create HVAC system representations using industry standard terminology and system, icon and typological representations and convert that unified representation into the format required by the whole building energy simulation tool EnergyPlus. This paper describes each stage of the conversion process, which involves transformations between the following representations: 1) engineer{\textquoteright}s representation, 2) component connectivity representation, 3) representation in the internal data model used in the Simergy graphical user interface for EnergyPlus, and 4) EnergyPlus representation.

The paper also describes mappings between these representations and the development of a rule-based validation and assignment framework required to implement that mapping. In addition, the paper describes the implementation of this process in Simergy.

}, author = {Tobias Maile and Mangesh Basarkar and James O{\textquoteright}Donnell and Philip Haves and Kevin Settlemyre} } @conference {2631, title = {An Assessment of the use of Building Energy Performance Simulation in Early Design}, booktitle = {IBPSA Building Simulation 2011}, year = {2011}, month = {11/2011}, address = {Sydney, Australia}, author = {Vladimir Bazjanac and Tobias Maile and Cody Rose and James O{\textquoteright}Donnell and Natasa Mrazovic and Elmer Morrissey and Welle, Benjamin} } @article {3181, title = {BacNet and Analog/Digital Interfaces of the Building Controls Virtual Testbed}, year = {2011}, month = {11/2011}, abstract = {

This paper gives an overview of recent developments in the Building Controls Virtual Test Bed (BCVTB), a framework for co-simulation and hardware-in-the-loop.

First, a general overview of the BCVTB is presented. Second, we describe the BACnet interface, a link which has been implemented to couple BACnet devices to the BCVTB. We present a case study where the interface was used to couple a whole building simulation program to a building control system to assess in real-time the performance of a real building. Third, we present the ADInterfaceMCC, an analog/digital interface that allows a USB-based analog/digital converter to be linked to the BCVTB. In a case study, we show how the link was used to couple the analog/digital converter to a building simulation model for local loop control.

}, author = {Philip Haves and Prajesh Bhattacharya and Thierry Stephane Nouidui and Michael Wetter and Zhengwei Li and Xiufeng Pang} } @proceedings {2785, title = {BACnet and Analog/Digital Interfaces of the Building Controls Virtual Test Bed}, year = {2011}, month = {11/2011}, pages = {p. 294-301}, address = {Sydney, Australia}, author = {Thierry Stephane Nouidui and Michael Wetter and Zhengwei Li and Xiufeng Pang and Prajesh Bhattacharya and Philip Haves} } @conference {2635, title = {Data Enviroments and Processing in Sem-Automated Simulation with EnergyPlus}, booktitle = {CIB W078-W102}, year = {2011}, address = {Sophia Antipolis, France}, author = {Vladimir Bazjanac and Tobias Maile and James O{\textquoteright}Donnell and Cody Rose and Natasa Mrazovic} } @conference {2633, title = {Development of a user interface for the EnergyPlus whole building energy simulation program}, booktitle = {IBPSA Building Simulation 2011}, year = {2011}, month = {11/2011}, address = {Sydney, Australia}, author = {Richard See and Philip Haves and Pramod Sreekanathan and Mangesh Basarkar and James O{\textquoteright}Donnell and Kevin Settlemyre} } @conference {2672, title = {Modeling and simulation of HVAC faults in EnergyPlus}, booktitle = {Building Simulation 2011}, year = {2011}, month = {11/2011}, address = {Australia}, keywords = {advanced building software: energyplus, building simulation, energyplus, faults, fouling, modeling, sensor offset, simulation research group}, author = {Mangesh Basarkar and Philip Haves and Xiufeng Pang and Liping Wang and Tianzhen Hong} } @article {3179, title = {Modeling and simulation of HVAC Results in EnergyPlus}, year = {2011}, month = {11/2011}, author = {Mangesh Basarkar and Xiufeng Pang and Liping Wang and Tianzhen Hong} } @proceedings {2787, title = {Real-time Building Energy Simulation using EnergyPlus and the Building Controls Virtual Test Bed}, year = {2011}, month = {11/2011}, pages = {p. 2890-2896}, address = {Sydney, Australia}, abstract = {

Most commercial buildings do not perform as well in practice as intended by the design and their performances often deteriorate over time. Reasons include faulty construction, malfunctioning equipment, incorrectly configured control systems and inappropriate operating procedures (Haves et al., 2001, Lee et al., 2007). To address this problem, the paper presents a simulation-based whole building performance monitoring tool that allows a comparison of building actual performance and expected performance in real time. The tool continuously acquires relevant building model input variables from existing Energy Management and Control System (EMCS). It then reports expected energy consumption as simulated of EnergyPlus. The Building Control Virtual Test Bed (BCVTB) is used as the software platform to provide data linkage between the EMCS, an EnergyPlus model, and a database. This paper describes the integrated real-time simulation environment. A proof-of-concept demonstration is also presented in the paper.

}, author = {Xiufeng Pang and Prajesh Bhattacharya and Zheng O{\textquoteright}Neill and Philip Haves and Michael Wetter and Trevor Bailey} } @conference {2630, title = {SimModel: A domain data model for whole building energy simulation}, booktitle = {IBPSA Building Simulation 2011}, year = {2011}, month = {10/2011}, abstract = {

Many inadequacies exist within industry-standard data models as used by present-day whole-building energy simulation software. Tools such as EnergyPlus and DOE-2 use custom schema definitions (IDD and BDL respectively) as opposed to standardized schema definitions (defined in XSD, EXPRESS, etc.). Non-standard data modes lead to a requirement for application developers to develop bespoke interfaces. Such tools have proven to be error prone in their implementation {\textendash} typically resulting in information loss.

This paper presents a Simulation Domain Model (SimModel) - a new interoperable XML-based data model for the building simulation domain. SimModel provides a consistent data model across all aspects of the building simulation process, thus preventing information loss. The model accounts for new simulation tool architectures, existing and future systems, components and features. In addition, it is a multi-representation model that enables integrated geometric and MEP simulation configuration data. The SimModel objects ontology moves away from tool-specific, non-standard nomenclature by implementing an industry-validated terminology aligned with Industry Foundation Classes (IFC).

The first implementation of SimModel supports translations from IDD, Open Studio IDD, gbXML and IFC. In addition, the EnergyPlus Graphic User Interface (GUI) employs SimModel as its internal data model. Ultimately, SimModel will form the basis for a new IFC Model View Definition (MVD) that will enable data exchange from HVAC Design applications to Energy Analysis applications. Extensions to SimModel could easily support other data formats and simulations (e.g. Radiance, COMFEN, etc.).

}, author = {James O{\textquoteright}Donnell and Richard See and Cody Rose and Tobias Maile and Vladimir Bazjanac and Philip Haves} } @conference {2634, title = {A software tool to compare measured and simulated building energy performance data}, booktitle = {IBPSA Building Simulation 2011}, year = {2011}, month = {11/2011}, address = {Sydney, Australia}, abstract = {

Building energy performance is often inadequate when compared to design goals. To link design goals to actual operation one can compare measured with simulated energy performance data. Our previously developed comparison approach is the Energy Performance Comparison Methodology (EPCM), which enables the identification of performance problems based on a comparison of measured and simulated performance data. In context of this method, we developed a software tool that provides graphing and data processing capabilities of the two performance data sets. The software tool called SEE IT (Stanford Energy Efficiency Information Tool) eliminates the need for manual generation of data plots and data reformatting. SEE IT makes the generation of time series, scatter and carpet plots independent of the source of data (measured or simulated) and provides a valuable tool for comparing measurements with simulation results. SEE IT also allows assigning data points on a predefined building object hierarchy and supports different versions of simulated performance data. This paper briefly introduces the EPCM, describes the SEE IT tool and illustrates its use in the context of a building case study.

}, author = {Tobias Maile and Vladimir Bazjanac and James O{\textquoteright}Donnell and Matthew Garr} } @proceedings {393, title = {Automated Continuous Commissioning of Commercial Buildings}, year = {2010}, month = {11/2010}, address = {Washington, D.C.}, author = {Trevor Bailey and Zheng O{\textquoteright}Neill and Madhusudana Shashanka and Prajesh Bhattacharya and Philip Haves and Xiufeng Pang} } @conference {244, title = {Development and Testing of Model Predictive Control for a Campus Chilled Water Plant with Thermal Storage}, booktitle = {2010 ACEEE Summer Study on Energy Efficiency in Buildings}, year = {2010}, publisher = {Omnipress}, organization = {Omnipress}, address = {Asilomar, California, USA}, abstract = {

A Model Predictive Control (MPC) implementation was developed for a university campus chilled water plant. The plant includes three water-cooled chillers and a two million gallon chilled water storage tank. The tank is charged during the night to minimize on-peak electricity consumption and take advantage of the lower ambient wet bulb temperature. A detailed model of the chilled water plant and simplified models of the campus buildings were developed using the equation-based modeling language Modelica. Steady state models of the chillers, cooling towers and pumps were developed, based on manufacturers{\textquoteright} performance data, and calibrated using measured data collected and archived by the control system. A dynamic model of the chilled water storage tank was also developed and calibrated. A semi-empirical model was developed to predict the temperature and flow rate of the chilled water returning to the plant from the buildings. These models were then combined and simplified for use in a MPC algorithm that determines the optimal chiller start and stop times and set-points for the condenser water temperature and the chilled water supply temperature. The paper describes the development and testing of the MPC implementation and discusses lessons learned and next steps in further research.

}, issn = {0-918249-60-0}, author = {Brian E. Coffey and Philip Haves and Michael Wetter and Brandon Hencey and Francesco Borrelli and Yudong Ma and Sorin Bengea} } @proceedings {241, title = {Model Predictive Control of Thermal Energy Storage in Building Cooling Systems}, year = {2010}, month = {06/2010}, address = {Baltimore, Maryland, USA}, abstract = {A model-based predictive control (MPC) is designed for optimal thermal energy storage in building cooling systems. We focus on buildings equipped with a water tank used for actively storing cold water produced by a series of chillers. Typically the chillers are operated at night to recharge the storage tank in order to meet the building demands on the following day. In this paper, we build on our previous work, improve the building load model, and present experimental results. The experiments show that MPC can achieve reductionin the central plant electricity cost and improvement of its efficiency.}, author = {Yudong Ma and Francesco Borrelli and Brandon Hencey and Brian E. Coffey and Sorin Bengea and Philip Haves} } @article {240, title = {Modeling and Measurement Constraints in Fault Diagnostics for HVAC Systems}, journal = {ASME Journal of Dynamic Systems, Measurement, and Controls}, year = {2010}, abstract = {Many studies have shown that energy savings of five to fifteen percent are achievable in commercial buildings by detecting and correcting building faults, and optimizing building control systems. However,in spite of good progress in developing tools for determining HVAC diagnostics, methods to detect faults in HVAC systems are still generally undeveloped. Most approaches use numerical filtering or parameter estimation methods to compare data from energy meters and building sensors to predictions from mathematical or statistical models. They are effective when models are relatively accurate and data contain few errors. In this paper, we address the case where models are imperfect and data are variable, uncertain, and can contain error. We apply a Bayesian updating approach that is systematic in managing and accounting for most forms of model and data errors. The proposed method uses both knowledge of first principle modeling and empirical results to analyze the system performance within the boundaries defined by practical constraints. We demonstrate the approach by detecting faults in commercial building air handling units. We find that the limitations that exist in air handling unit diagnostics due to practical constraints can generally be effectively addressed through the proposed approach.}, author = {Massieh Najafi and David M. Auslander and Peter L. Bartlett and Philip Haves and Michael D. Sohn} } @article {214, title = {Anisotropy invariant Reynolds stress model of turbulence (AIRSM) and its application on attached and separated wall-bounded flows}, journal = {Flow, Turbulence and Combustion}, volume = {83}, year = {2009}, month = {07/2009}, pages = {81-103}, chapter = {81}, abstract = {

Numerical predictions with a differential Reynolds stress closure, which in its original formulation explicitly takes into account possible states of turbulence on the anisotropy-invariant map, are presented. Thus the influence of anisotropy of turbulence on the modeled terms in the governing equations for the Reynolds stresses is accounted for directly. The anisotropy invariant Reynolds stress model (AIRSM) is implemented and validated in different finite-volume codes. The standard wall-function approach is employed as initial step in order to predict simple and complex wall-bounded flows undergoing large separation. Despite the use of simple wall functions, the model performed satisfactory in predicting these flows. The predictions of the AIRSM were also compared with existing Reynolds stress models and it was found that the present model results in improved convergence compared with other models. Numerical issues involved in the implementation and application of the model are also addressed.

}, keywords = {Anisotrpoy, Invariant map, Reynolds stress model, Reynolds-averaged Navier-Stokes, Separated wall-bounded flow, Turbulence, Turbulence modeling}, issn = {1573-1987}, doi = {10.1007/s10494-008-9190-y}, author = {V. Kumar and Bettina Frohnapfel and Jovan Jovanovi{\'c} and Michael Breuer and Wangda Zuo and Ibrahim Hadzi{\'c} and Richard Lechner} } @proceedings {394, title = {{\textquotedblleft}The Monitoring,{\textquotedblright} Panel: Chill-Off}, year = {2009}, month = {10/2009}, address = {Sunnyvale, CA}, author = {Dean Nelson and Brian Day and Geoffrey C. Bell and Prajesh Bhattacharya and Mike Ryan} } @conference {2638, title = {Pervasive Knowledge-Based Networking for Maintenance Inspection in Smart Buildings}, booktitle = {MUCS 2009: 6th IEEE International Workshop on Managing Ubiquitous Communications and Services}, year = {2009}, address = {Barcelona, Spain}, author = {Paul Mara and Declan O{\textquoteright}Sullivan and Rob Brennan and Marcus Keane and Kris McGlinn and James O{\textquoteright}Donnell} } @article {239, title = {Towards a Very Low Energy Building Stock: Modeling the US Commercial Building Stock to Support Policy and Innovation Planning}, journal = {Building Research and Information}, volume = {37:5}, year = {2009}, chapter = {610}, abstract = {

This paper describes the origin, structure and continuing development of a model of time varying energy consumption in the US commercial building stock. The model is based on a flexible structure that disaggregates the stock into various categories (e.g. by building type, climate, vintage and life-cycle stage) and assigns attributes to each of these (e.g. floor area and energy use intensity by fuel type and end use), based on historical data and user-defined scenarios for future projections. In addition to supporting the interactive exploration of building stock dynamics, the model has been used to study the likely outcomes of specific policy and innovation scenarios targeting very low future energy consumption in the building stock. Model use has highlighted the scale of the challenge of meeting targets stated by various government and professional bodies, and the importance of considering both new construction and existing buildings.

}, author = {Brian E. Coffey and Sam Borgeson and Stephen E. Selkowitz and Joshua S. Apte and Paul A. Mathew and Philip Haves} } @proceedings {247, title = {Application of Machine Learning in Fault Diagnostics of Mechanical Systems}, year = {2008}, month = {10/2008}, author = {Massieh Najafi and David M. Auslander and Peter L. Bartlett and Philip Haves} } @article {413, title = {Comparing computer run time of building simulation programs}, journal = {Building Simulation}, volume = {1}, year = {2008}, month = {2008}, pages = {210-213}, abstract = {

This paper presents an approach to comparing computer run time of building simulation programs. The computing run time of a simulation program depends on several key factors, including the calculation algorithm and modeling capabilities of the program, the run period, the simulation time step, the complexity of the energy models, the run control settings, and the software and hardware configurations of the computer that is used to make the simulation runs. To demonstrate the approach, simulation runs are performed for several representative DOE-2.1E and EnergyPlus energy models. The computer run time of these energy models are then compared and analyzed.

}, keywords = {computer run time, doe-2, energyplus, simulation program}, doi = {10.1007/s12273-008-8123-y}, author = {Tianzhen Hong and Walter F. Buhl and Philip Haves and Stephen E. Selkowitz and Michael Wetter} } @proceedings {395, title = {Convergence of IT and Facilities Real-Time and Historic Data Leads to Data Center Efficiency}, year = {2008}, month = {05/2008}, address = {Orlando, FL}, author = {Prajesh Bhattacharya} } @article {419, title = {EnergyPlus Analysis Capabilities for Use in Title 24}, year = {2008}, month = {2008}, institution = {LBNL}, keywords = {building simulation, code compliance, energyplus, title 24}, issn = {LBNL-822E}, url = {http://www.escholarship.org/uc/item/0z78090x}, author = {Tianzhen Hong and Walter F. Buhl and Philip Haves} } @article {420, title = {EnergyPlus Run Time Analysis}, year = {2008}, month = {2008}, institution = {LBNL}, issn = {LBNL-1311E, CEC-500-2008-094}, url = {http://escholarship.org/uc/item/36h4m5z0}, author = {Tianzhen Hong and Walter F. Buhl and Philip Haves} } @proceedings {246, title = {Fault Diagnostics and Supervised Testing: How Fault Diagnostic tools can be Proactive?}, year = {2008}, month = {11/2008}, abstract = {The topic of fault detection and diagnostics (FDD) is studied from the perspective of proactive testing. Unlike most research focus in the diagnosis area in which system outputs are analyzed for diagnosis purposes, in this paper the focus is on the other side of the problem: manipulating system inputs for better diagnosis reasoning. In other words, the question of how diagnostic mechanisms can direct system inputs for better diagnosis analysis is addressed here. It is shown how the problem can be formulated as decision making problem coupled with a Bayesian Network based diagnostic mechanism. The developed mechanism is applied to the problem of supervised testing in HVAC systems.}, url = {http://www.actapress.com/Content_of_Proceeding.aspx?proceedingID=503}, author = {Massieh Najafi and David M. Auslander and Peter L. Bartlett and Philip Haves} } @conference {2648, title = {IFC BIM-based Methodology for Semi-Automated Building Energy Performance Simulation}, booktitle = {CIB W78, Proc. 25th conf}, year = {2008}, month = {07/2008}, address = {Santiago, Chile}, author = {Vladimir Bazjanac} } @proceedings {245, title = {Overcoming the Complexity of Diagnostic Problems due to Sensor Network Architecture}, year = {2008}, month = {11/08}, abstract = {

In fault detection and diagnostics, limitations coming from the sensor network architecture are one of the main challenges in evaluating a system{\textquoteright}s health status. Usually the design of the sensor network architecture is not solely based on diagnostic purposes, other factors like controls, financial constraints, and practical limitations are also involved. As a result, it quite common to have one sensor (or one set of sensors) monitoring the behaviour of two or more components. This can significantly extend the complexity of diagnostic problems. In this paper a systematic approach is presented to deal with such complexities. It is shown how the problem can be formulated as a Bayesian network based diagnostic mechanism with latent variables. The developed approach is also applied to the problem of fault diagnosis in HVAC systems, an application area with considerable modeling and measurement constraints.

}, url = {https://www.actapress.com/Content_Of_Proceeding.aspx?ProceedingID=503}, author = {Massieh Najafi and David M. Auslander and Peter L. Bartlett and Philip Haves} } @conference {415, title = {Reducing Energy Use In Florida Buildings}, booktitle = {16th Symposium on Improving Building Systems in Hot and Humid Climates, December 15-17, 2008}, year = {2008}, month = {12/2008}, address = {Dallas, TX}, abstract = {

The 2007 Florida Building Code (ICC, 2008) requires building designers and architects to achieve a minimum energy efficiency rating for commercial buildings located throughout Florida. Although the Florida Building Code is strict in the minimum requirements for new construction, several aspects of building construction can be further improved through careful thought and design. This report outlines several energy saving features that can be used to ensure that new buildings meet a new target goal of 85\% energy use compared to the 2007 energy code in order to achieve Governor Crist{\textquoteright}s executive order to improve the energy code by 15\%.

To determine if a target goal of 85\% building energy use is attainable, a computer simulation study was performed to determine the energy saving features available which are, in most cases, stricter than the current Florida Building Code. The energy savings features include improvements to building envelop, fenestration, lighting and equipment, and HVAC efficiency. The imp acts of reducing outside air requirements and employing solar water heating were also investigated. Th e purpose of the energy saving features described in this document is intended to provide a simple, prescriptive method for reducing energy consumption using the methodology outlined in ASHRAE Standard 90.1 (ASHRAE, 2007).

There are two difficulties in trying to achieve savings in non-residential structures. First, there is significant energy use caused by internal loads for people and equipment and it is difficult to use the energy code to achieve savings in this area relative to a baseline. Secondly, the ASHRAE methodology uses some of the same features that are proposed for the new building, so it may be difficult to claim savings for some strategies that will produce savings such as improved ventilation controls, reduced window area, or reduced plug loads simply because the methodology applies those features to the comparison reference building.

Several measures to improve the building envelope characteristics were simulated. Simply using the selected envelope measures resulted in savings of less than 10\% for all building types. However, if such measures are combined with aggressive lighting reductions and improved efficiency HVAC equipment and controls, a target savings of 15\% is easily attainable.

}, author = {Richard Raustad and Mangesh Basarkar and Robin K. Vieira} } @conference {2649, title = {Specification of an Information Delivery Tool to Support Optimal Holistic Environmental and Energy Management in Buildings}, booktitle = {SimBuild 2008}, year = {2008}, month = {07/2008}, address = {Berkeley, CA, USA}, author = {James O{\textquoteright}Donnell and Marcus Keane and Vladimir Bazjanac} } @article {377, title = {Unlocking Historical Data in Critical IT}, journal = {Data Center Dynamics Focus}, year = {2008}, month = {12/2008}, author = {Prajesh Bhattacharya} } @conference {2639, title = {Utilisation of Whole Building Energy Simulation Output to Provide Optimum Decision Support for Building Managers}, booktitle = {SimBuild 2008}, year = {2008}, address = {Berkeley, CA}, author = {James O{\textquoteright}Donnell and Marcus Keane and Vladimir Bazjanac} } @conference {380, title = {Coverage Problem for Sensors Embedded in Temperature Sensitive Environments}, booktitle = {IEEE Infocom, 2007}, year = {2007}, month = {5/2007}, address = {Anchorage, AL}, author = {Arunabha Sen and Nibedita Das and Ling Zhou and Bao Hong Shen and Sudheendra Murthy and Prajesh Bhattacharya} } @article {3389, title = {Energy Performance of Underfloor Air Distribution Systems}, year = {2007}, institution = {California Energy Commission - Public Interest Energy Research Program}, author = {Fred S. Bauman and Thomas L. Webster and Hui Jin and Wolfgang Lukaschek and Corinne Benedek and Edward A. Arens and Paul F. Linden and Anna Lui and Walter F. Buhl and Darryl J. Dickerhoff} } @conference {2663, title = {Global Efficiency of Direct Flow Vacuum Collectors in Autonomous Solar Desiccant Cooling: Simulation and Experimental Results}, booktitle = {Proc. Building Simulation 2007}, year = {2007}, month = {09/2007}, address = {Beijing, China}, author = {Paul Bourdoukan and Etienne Wurtz and Maurice Sp{\'e}randio and Patrice Joubert} } @article {379, title = {Brownian Motion Based Convective- Conductive Model for the Effective Thermal Conductivity of Nanofluids}, journal = {Journal of Heat Transfer}, volume = {128}, year = {2006}, pages = {588-595}, chapter = {588}, author = {Ravi S. Prasher and Prajesh Bhattacharya and Patrick E. Phelan} } @proceedings {396, title = {Carbon Nanotube (CNT)-Centric Thermal Management of Future High Power Microprocessors}, year = {2006}, month = {03/2006}, address = {Atlanta, GA}, author = {Prajesh Bhattacharya and Wei, X. and Andrei G. Fedorov and Yogendra K. Joshi and Navdeep Bajwa and Anyuan Cao and Pulickel Ajayan} } @proceedings {2809, title = {A Case Study Demonstrating the Utility of Inter-Program Comparative Testing for Diagnosing Errors in Building Simulation Programs}, year = {2006}, month = {05/2006}, address = {Toronto, Canada}, author = {Andreas Weber and Ian Beausoleil-Morrison and Brent T. Griffith and Teemu Vesanen and S{\'e}bastien Lerson} } @article {378, title = {Characterization of the Temperature Oscillation Technique to Measure the Thermal Conductivity of Fluids}, journal = {International Journal of Heat and Mass Transfer}, volume = {49}, year = {2006}, month = {08/2006}, pages = {2950-2956}, chapter = {2950}, abstract = {

The temperature oscillation technique to measure the thermal diffusivity of a fluid consists of filling a cylindrical volume with the fluid, applying an oscillating temperature boundary condition at the two ends of the cylinder, measuring the amplitude and phase of the temperature oscillation at any point inside the cylinder, and finally calculating the fluid thermal diffusivity from the amplitude and phase values of the temperature oscillations at the ends and at the point inside the cylinder. Although this experimental technique was introduced by Santucci and co-workers nearly two decades ago, its application is still limited, perhaps because of the perceived difficulties in obtaining accurate results. Here, we attempt to clarify this approach by first estimating the maximum size of the liquid{\textquoteright}s cylindrical volume, performing a systematic series of experiments to find the allowable amplitude and frequency of the imposed temperature oscillations, and then validating our experimental setup and the characterization method by measuring the thermal conductivity of pure water at different temperatures and comparing our results with previously published work.

}, keywords = {Temperature oscillation technique, Thermal conductivity, thermal diffusivity}, url = {http://www.sciencedirect.com/science/article/pii/S001793100600144X}, author = {Prajesh Bhattacharya and S. Nara and P. Vijayan and Tang, T. and W. Lai and Patrick E. Phelan and Ravi S. Prasher and David W. Song and J. Wang} } @article {378, title = {Characterization of the Temperature Oscillation Technique to Measure the Thermal Conductivity of Fluids}, journal = {International Journal of Heat and Mass Transfer}, volume = {49}, year = {2006}, month = {08/2006}, pages = {2950-2956}, chapter = {2950}, abstract = {

The temperature oscillation technique to measure the thermal diffusivity of a fluid consists of filling a cylindrical volume with the fluid, applying an oscillating temperature boundary condition at the two ends of the cylinder, measuring the amplitude and phase of the temperature oscillation at any point inside the cylinder, and finally calculating the fluid thermal diffusivity from the amplitude and phase values of the temperature oscillations at the ends and at the point inside the cylinder. Although this experimental technique was introduced by Santucci and co-workers nearly two decades ago, its application is still limited, perhaps because of the perceived difficulties in obtaining accurate results. Here, we attempt to clarify this approach by first estimating the maximum size of the liquid{\textquoteright}s cylindrical volume, performing a systematic series of experiments to find the allowable amplitude and frequency of the imposed temperature oscillations, and then validating our experimental setup and the characterization method by measuring the thermal conductivity of pure water at different temperatures and comparing our results with previously published work.

}, keywords = {Temperature oscillation technique, Thermal conductivity, thermal diffusivity}, url = {http://www.sciencedirect.com/science/article/pii/S001793100600144X}, author = {Prajesh Bhattacharya and S. Nara and P. Vijayan and Tang, T. and W. Lai and Patrick E. Phelan and Ravi S. Prasher and David W. Song and J. Wang} } @conference {416, title = {Dehumidification Enhancement of Direct Expansion Systems through Component Augmentation of the Cooling Coil}, booktitle = {Fifteenth Symposium on Improving Building Systems in Hot and Humid Climates, July 24-26, 2006}, year = {2006}, address = {Orlando, FL}, abstract = {

Diverse air conditioning products with enhanced dehumidification features are being introduced to meet the increased moisture laden ventilation air requirements of ASHRAE Standard 62 in humid climates. In this evaluation, state point performance spreadsheet models for single path, mixed air packaged systems compare a conventional "off the shelf" direct expansion (DX) cooling system and its performance to systems that augment the DX coil with enhanced dehumidification components, such as heat exchangers and desiccant dehumidifiers. Using common performance metrics for comparisons at ARI rating conditions, these alternative systems define a best practice for enhanced dehumidification performance. The state point performance spreadsheet models combine available algorithms from the EnergyPlus{\texttrademark} simulation program for DX coils and heat exchangers with newly developed algorithms for desiccant dehumidifiers. All the models and their algorithms are applied in EnergyPlus{\texttrademark} for simulations of annual system cooling performance, including sensible and latent loads met, energy consumed, and humidity levels maintained, in select building types and climatic locations. Per this EnergyPlus{\texttrademark} analysis, these enhanced dehumidification systems present challenging decision-making tradeoffs between humidity control improvements over conventional DX systems, condensing (compressor) unit energy consumption reductions versus DX cool and reheat approaches, and fan energy use increases due to the additional component pressure drops.

}, author = {Douglas Kosar and Don Shirey and Mangesh Basarkar and Muthasamy Swami and Richard Raustad} } @proceedings {3391, title = {Development of a Model Specification for Performance Monitoring Systems for Commercial Buildings}, year = {2006}, month = {08/2006}, address = {Pacific Grove, CA, USA}, author = {Philip Haves and Robert J. Hitchcock and Kenneth L. Gillespie and Martha Brook and Christine Shockman and Joseph J Deringer and Kristopher L. Kinney} } @proceedings {268, title = {Development of a Model Specification for Performance Monitoring Systems for Commercial Buildings}, year = {2006}, month = {08/2006}, address = {Asilomar, California, USA}, abstract = {

The paper describes the development of a model specification for performance monitoring systems for commercial buildings. The specification focuses on four key aspects of performance monitoring: performance metrics measurement system requirements data acquisition and archiving data visualization and reporting The aim is to assist building owners in specifying the extensions to their control systems that are required to provide building operators with the information needed to operate their buildings more efficiently and to provide automated diagnostic tools with the information required to detect and diagnose faults and problems that degrade energy performance. The paper reviews the potential benefits of performance monitoring, describes the specification guide and discusses briefly the ways in which it could be implemented. A prototype advanced visualization tool is also described, along with its application to performance monitoring. The paper concludes with a description of the ways in which the specification and the visualization tool are being disseminated and deployed.

}, url = {http://www.aceee.org/proceedings-paper/ss06/panel03/paper10}, author = {Philip Haves and Robert J. Hitchcock and Kenneth L. Gillespie and Martha Brook and Christine Shockman and Joseph J Deringer and Kristopher L. Kinney} } @article {381, title = {Effect of Aggregation Kinetics on the Thermal Conductivity of Nanoscale Colloidal Solutions (Nanofluids)}, journal = {Nanoletters}, volume = {6}, year = {2006}, pages = {1529-1534}, chapter = {1529}, author = {Ravi S. Prasher and Prajesh Bhattacharya and Patrick E. Phelan} } @conference {382, title = {Effect of Coloidal Chemistry on the Thermal Conductivity of Nanofluids}, booktitle = {International Mechanical Engineering Congress \& Exposition}, year = {2006}, month = {11/2006}, address = {Chicago, IL}, author = {Ravi S. Prasher and Prajesh Bhattacharya and Patrick E. Phelan} } @article {383, title = {Enhanced Mass Transport in Nanofluids}, journal = {Nanoletters}, volume = {6}, year = {2006}, month = {03/2006}, pages = {419-423}, chapter = {419}, abstract = {

Thermal conductivity enhancement in nanofluids, which are liquids containing suspended nanoparticles, has been attributed to localized convection arising from the nanoparticles{\textquoteright} Brownian motion. Because convection and mass transfer are similar processes, the objective here is to visualize dye diffusion in nanofluids. It is observed that dye diffuses faster in nanofluids compared to that in water, with a peak enhancement at a nanoparticle volume fraction, φ, of 0.5\%. A possible change in the slope of thermal conductivity enhancement at that same φ signifies that convection becomes less important at higher φ. The enhanced mass transfer in nanofluids can be utilized to improve diffusion in microfluidic devices.

}, doi = {10.1021/nl0522532}, author = {S. Krishnamurthy and Prajesh Bhattacharya and Patrick E. Phelan and Ravi S. Prasher} } @proceedings {3393, title = {Evaluation of Methods for Determining Demand-Limiting Setpoint Trajectories in Commercial Buildings Using Short-Term Data Analysis}, year = {2006}, month = {08/2006}, address = {Cambridge, MA, USA}, author = {Kyoung-ho Lee and James E. Braun} } @conference {417, title = {IFC to CONTAM Translator}, booktitle = {SimBuild 2006}, year = {2006}, month = {08/2006}, address = {Boston, MA}, author = {Mangesh Basarkar and Muthasamy Swami} } @proceedings {3396, title = {Using EnergyPlus for California Title-24 Compliance Calculations}, year = {2006}, month = {08/2006}, address = {Cambridge, MA, USA}, author = {Yu Joe Huang and Norman Bourassa and Walter F. Buhl and Ender Erdem and Robert J. Hitchcock} } @conference {1945, title = {Using EnergyPlus for California Title-24 compliance calculations}, booktitle = {SimBuild 2006}, year = {2006}, month = {08/2006}, address = {Cambridge, MA}, abstract = {

For the past decade, the non-residential portion of California{\textquoteright}s Title-24 building energy standard has relied on DOE-2.1E as the reference computer simulation program for development as well as compliance. However, starting in 2004, the California Energy Commission has been evaluating the possible use of EnergyPlus as the reference program in future revisions of Title-24. As part of this evaluation, the authors converted the Alternate Compliance Method (ACM) certification test suite of 150 DOE-2 files to EnergyPlus, and made parallel DOE-2 and EnergyPlus runs for this extensive set of test cases. A customized version of DOE-2.1E named doe2ep was developed to automate the conversion process. This paper describes this conversion process, including the difficulties in establishing an apples-to-apples comparison between the two programs, and summarizes how the DOE-2 and EnergyPlus results compare for the ACM test cases.

}, author = {Yu Joe Huang and Norman Bourassa and Walter F. Buhl and Ender Erdem and Robert J. Hitchcock} } @proceedings {397, title = {Computational Analysis of the Colloidal Stability of Nanofluids}, year = {2005}, month = {11/2005}, address = {Orlando, FL}, author = {Prajesh Bhattacharya and Patrick E. Phelan and Ravi S. Prasher} } @conference {2665, title = {Design of the Natural Ventilation System for the New San Diego Children{\textquoteright}s Museum}, booktitle = {IBPSA Building Simulation 2005}, year = {2005}, month = {08/2005}, address = {Montreal, Canada}, author = {Guilherme Carrilho da Gra{\c c}a and Paul F. Linden and Martha Brook} } @conference {388, title = {Effect of Particle Material on the Static Thermal Conductivity of Nanofluids}, booktitle = {Heat Transfer Conference}, year = {2005}, month = {07/2005}, address = {San Francisco, CA}, author = {P. Vijayan and Prajesh Bhattacharya and S. Nara and W. Lai and Patrick E. Phelan and Ravi S. Prasher and David W. Song and J. Wang} } @conference {385, title = {Experimental Determination of the Effect of Varying Base Fluid and Temperature on the Static Thermal Conductivity of Nanofluids}, booktitle = {ASME International Mechanical Engineering Congress and Exposition, November 5-11, 2005}, year = {2005}, month = {11/2005}, publisher = {ASME}, organization = {ASME}, address = {Orlando, FL}, abstract = {

The heat transfer abilities of fluids can be improved by adding small particles of sizes of the order of nanometers. Recently a lot of research has been done in evaluating the thermal conductivity of nanofluids using various nanoparticles. In our present work we address this issue by conducting a series of experiments to determine the effective thermal conductivity of alumina-nanofluids by varying the base fluid with water and antifreeze liquids like ethylene glycol and propylene glycol. Temperature oscillation method is used to find the thermal conductivity of the nanofluid. The results show the thermal conductivity enhancement of nanofluids depends on viscosity of the base fluid. Finally the results are validated with a recently proposed theoretical model.

}, isbn = {0-7918-4221-5}, doi = {10.1115/IMECE2005-81494}, author = {S. Nara and Prajesh Bhattacharya and P. Vijayan and W. Lai and W. Rosenthal and Patrick E. Phelan and Ravi S. Prasher and David W. Song and Jinlin Wang} } @article {387, title = {Thermal Conductivity of Nanoscale Colloidal Solutions (Nanofluids)}, journal = {Physical Review Letters}, volume = {94}, year = {2005}, chapter = {025901-1}, author = {Ravi S. Prasher and Prajesh Bhattacharya and Patrick E. Phelan} } @article {386, title = {Brownian Dynamics Simulation to Determine the Effective Thermal Conductivity of Nanofluids}, journal = {Journal of Applied Physics}, volume = {95}, year = {2004}, month = {06/2004}, pages = {6492{\textendash}6494}, chapter = {6492}, abstract = {

A nanofluid is a fluid containing suspended solid particles, with sizes on the order of nanometers. Normally, nanofluids have higher thermal conductivities than their base fluids. Therefore, it is of interest to predict the effective thermal conductivity of such a nanofluid under different conditions, especially since only limited experimental data are available. We have developed a technique to compute the effective thermal conductivity of a nanofluid using Brownian dynamics simulation, which has the advantage of being computationally less expensive than molecular dynamics, and have coupled that with the equilibrium Green-Kubo method. By comparing the results of our calculation with the available experimental data, we show that our technique predicts the thermal conductivity of nanofluids to a good level of accuracy.

}, keywords = {complex fluids, Disperse systems, Thermal conduction in nonmetallic liquids}, doi = {10.1063/1.1736319}, author = {Prajesh Bhattacharya and Saha, S.K. and Ajay K. Yadav and Patrick E. Phelan and Ravi S. Prasher} } @article {11592, title = {Building energy performance simulation as part of interoperable software environments}, journal = {Building and Environment}, volume = {39}, number = {8}, year = {2004}, pages = {879-883}, author = {Vladimir Bazjanac} } @article {3403, title = {Building Energy Performance Simulation as Part of Interoperable Software Environments}, journal = {Building and Environment}, volume = {39}, year = {2004}, month = {2004}, pages = {879-883}, chapter = {879}, author = {Vladimir Bazjanac} } @conference {2644, title = {BuildingPI: A Future Tool for Building Life Cycle Analysis}, booktitle = {SimBuild 2004 1st International Conference of IBPSA-USA}, year = {2004}, month = {08/2004}, address = {Boulder, Colorado, USA}, author = {James O{\textquoteright}Donnell and Elmer Morrissey and Marcus Keane and Vladimir Bazjanac} } @conference {389, title = {Determining the Effective Viscosity of a Nanofluid Using Brownian Dynamics Simulation}, booktitle = {1st International Symposium on Micro \& Nano Technology}, year = {2004}, month = {03/2004}, address = {Honolulu, HI}, author = {Prajesh Bhattacharya and Patrick E. Phelan and Ravi S. Prasher} } @proceedings {2823, title = {EnergyPlus: An Update}, year = {2004}, month = {08/2004}, address = {Boulder, Colorado, USA}, author = {Drury B. Crawley and Linda K. Lawrie and Curtis O. Pedersen and Frederick C. Winkelmann and Michael J. Witte and Richard K. Strand and Richard J. Liesen and Walter F. Buhl and Yu Joe Huang and Robert H. Henninger and Jason Glazer and Daniel E. Fisher and Don B. Shirley and Brent T. Griffith and Peter G. Ellis and Lixing Gu} } @conference {390, title = {Evaluation of the Temperature Oscillation Technique to Calculate Thermal Conductivity of Water and Systematic Measurement of the Thermal Conductivity of Aluminum Oxide {\textendash} Water Nanofluiids}, booktitle = {International Mechanical Engineering Congress \& Exposition,}, year = {2004}, month = {11/2004}, address = {Anaheim, CA}, author = {Prajesh Bhattacharya and P. Vijayan and Tang, T. and S. Nara and Patrick E. Phelan and Ravi S. Prasher and J. Wang and David W. Song} } @proceedings {3401, title = {IFC HVAC Interface to EnergyPlus: A Case of Expanded Interoperability for Energy Simulation}, year = {2004}, month = {08/2004}, address = {Boulder, Colorado, USA}, author = {Vladimir Bazjanac and Tobias Maile} } @conference {11938, title = {IFC HVAC interface to EnergyPlus - A case of expanded interoperability for energy simulation}, booktitle = {SimBuild 2004}, year = {2004}, month = {08/2004}, address = {Boulder, CO}, author = {Vladimir Bazjanac and Tobias Maile} } @proceedings {398, title = {Numerical Tools For Particle- Fluid Interactions}, year = {2004}, month = {02/2004}, author = {R. Calhoun and Patrick E. Phelan and Ajay K. Yadav and Prajesh Bhattacharya} } @conference {56064, title = {Peak Demand Reduction from Pre-Cooling with Zone Temperature Reset in an Office Building}, booktitle = {2004 ACEEE Summer Study on Energy Efficiency in Buildings}, year = {2004}, month = {08/2004}, address = {Pacific Grove, CA}, abstract = {

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 ft2 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/ft2) 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.

}, keywords = {demand shifting (pre-cooling)}, author = {Peng Xu and Philip Haves and Mary Ann Piette and James E. Braun} } @proceedings {2828, title = {Simulation of Tubular Daylighting Devices and Daylighting Shelves in EnergyPlus}, year = {2004}, month = {08/2004}, address = {Boulder, Colorado, USA}, author = {Peter G. Ellis and Richard K. Strand and Kurt T. Baumgartner} } @proceedings {3402, title = {Specification and Implementation of IFC Based Performance Metrics to Support Building Life Cycle Assessment of Hybrid Energy Systems}, year = {2004}, month = {08/2004}, address = {Boulder, Colorado, USA}, author = {Elmer Morrissey and James O{\textquoteright}Donnell and Marcus Keane and Vladimir Bazjanac} } @conference {1835, title = {Specification and Implementation of IFC Based Performance Metrics to Support Building Life Cycle Assessment of Hybrid Energy Systems}, booktitle = {SimBuild 2004: Building Sustainability and Performance Through Simulation}, year = {2004}, month = {08/2004}, address = {Boulder, CO}, author = {Elmer Morrissey and James O{\textquoteright}Donnell and Marcus Keane and Vladimir Bazjanac} } @proceedings {3400, title = {Specification and Implementation of IFC-Based Performance Metrics to Support Building Life Cycle Assessment of Hybrid Energy Systems}, year = {2004}, month = {08/2004}, address = {Boulder, Colorado, USA}, author = {Elmer Morrissey and James O{\textquoteright}Donnell and Marcus Keane and Vladimir Bazjanac} } @conference {2645, title = {Specification of IFC Based Performance Metrics to Support Building Life Cycle Analysis of Hybrid Energy Systems}, booktitle = {SimBuild 2004 1st International Conference of IBPSA-USA}, year = {2004}, month = {08/2004}, address = {Boulder, Colorado, USA}, author = {Elmer Morrissey and James O{\textquoteright}Donnell and Marcus Keane and Vladimir Bazjanac} } @conference {1955, title = {Virtual Building Environments - Applying Information Modeling to Buildings}, booktitle = {European Conference on Product and Process Modeling in the Building and Construction Industry (ECPPM) 2004}, year = {2004}, month = {09/2004}, address = {Istanbul, Turkey}, abstract = {

A Virtual Building Environment (VBE) is a place where building industry project staffs can get help in creating Building Information Models (BIM) and in the use of virtual buildings. It consists of a group of industry software that is operated by industry experts who are also experts in the use of that software. The purpose of a VBE is to facilitate expert use of appropriate software applications in conjunction with each other to efficiently support multidisciplinary work. This paper defines BIM and virtual buildings, and describes VBE objectives, set-up and characteristics of operation. It informs about the VBE Initiative and the benefits from a couple of early VBE projects.

}, author = {Vladimir Bazjanac} } @conference {391, title = {Determining the Effective Thermal Conductivity of a Nanofluid Using Brownian Dynamics Simulation}, booktitle = {National Heat Transfer Conference}, year = {2003}, month = {07/2003}, address = {Las Vegas, NV}, author = {Prajesh Bhattacharya and Saha, S.K. and Ajay K. Yadav and Patrick E. Phelan and Ravi S. Prasher} } @article {288, title = {Field Testing Model-Based Condition Monitoring on a HVAC Cooling Coil Sub-System}, journal = {Building Services Engineering Research \& Technology}, volume = {24}, year = {2003}, pages = {103-116}, author = {Richard A. Buswell and Philip Haves and Jonathan A. Wright} } @conference {11947, title = {Improving building energy performance simulation with software interoperability}, booktitle = {Building Simulation 2003}, volume = {1}, year = {2003}, month = {08/2003}, address = {Eindhoven, Netherlands}, author = {Vladimir Bazjanac} } @conference {301, title = {A Computer Simulation Appraisal of Non-Residential Low Energy Cooling Systems in California}, booktitle = {2002 ACEEE Summer Study on Energy Efficiency in Buildings}, year = {2002}, month = {08/2002}, address = {Asilomar, California, USA}, abstract = {

An appraisal of the potential performance of different Low Energy Cooling (LEC) systems in nonresidential buildings in California is being conducted using computer simulation. The paper presents results from the first phase of the study, which addressed the systems that can be modeled, with the DOE-2.1E simulation program.

The following LEC technologies were simulated as variants of a conventional variable-air-volume system with vapor compression cooling and mixing ventilation in the occupied spaces:

Results are presented for four populous climates, represented by Oakland, Sacramento, Pasadena and San Diego. The greatest energy savings are obtained from a combination of displacement ventilation and air-side indirect/direct evaporative pre-cooling. Cool beam systems have the lowest peak demand but do not reduce energy consumption significantly because the reduction in fan energy is offset by a reduction in air-side free cooling. Overall, the results indicate significant opportunities for LEC technologies to reduce energy consumption and demand in non-residential new construction and retrofit.

}, author = {Norman Bourassa and Philip Haves and Yu Joe Huang} } @proceedings {297, title = {HVAC Component Data Modeling Using Industry Foundation Classes}, year = {2002}, month = {12/2002}, address = {Li{\`e}ge, Belgium}, abstract = {

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.

}, author = {Vladimir Bazjanac and James Forester and Philip Haves and Darko Sucic and Peng Xu} } @proceedings {399, title = {Modeling the Behavior of F1-ATPase Biomolecular Motors Using Brownian Dynamics Simulation}, year = {2002}, month = {09/2002}, address = {Scottsdale, AZ}, author = {Prajesh Bhattacharya and Patrick E. Phelan} } @proceedings {298, title = {Non-Linear Recursive Parameter Estimation Applied to Fault Detection and Diagnosis in Real Buildings}, year = {2002}, month = {12/2002}, address = {Li{\`e}ge, Belgium}, author = {Richard A. Buswell and Philip Haves and Tim I. Salsbury and Jonathan A. Wright} } @conference {392, title = {Understanding the Behavior of an F1-ATPase Biomolecular Motor Using Brownian Dynamics Simulation}, booktitle = {US-Japan Nanotherm Seminar: Nanoscale Thermal Science and Engineering}, year = {2002}, month = {06/2002}, address = {Berkeley, CA}, author = {Prajesh Bhattacharya and Patrick E. Phelan} } @article {422, title = {Building simulation: an overview of development and information sources}, journal = {Building and Environment}, volume = {35}, year = {2000}, month = {05/2000}, pages = {347-361}, type = {Review Article}, chapter = {347}, abstract = {

We review the state-of-the-art on the development and application of computer-aided building simulation by addressing some crucial questions in the field. Although the answers are not intended to be comprehensive, they are sufficiently varied to provide an overview ranging from the historical and technical development to choosing a suitable simulation program and performing building simulation. Popular icons of major interested agencies and simulation tools and key information sources are highlighted. Future trends in the design and operation of energy-efficient {\textquoteleft}green{\textquoteright} buildings are briefly described.

}, keywords = {building simulation}, doi = {10.1016/S0360-1323(99)00023-2}, author = {Tianzhen Hong and Siaw K. Chou and T.Y. Bong} } @article {423, title = {A design day for building load and energy estimation}, journal = {Building and Environment}, volume = {34}, year = {1999}, month = {07/1999}, pages = {469-477}, chapter = {469}, abstract = {

We describe how a design day for building energy performance simulation can be selected from a typical meteorological year of a location. The advantages of the design day weather file are its simplicity and flexibility in use with simulation programs. The design day is selected using a weather parameter comprising the daily average dry bulb temperature and total solar insolation. The selection criterion addresses the balance between the need to minimise the part-load performance of the air-conditioning systems and plants and the number of hours of load not met. To validate the versatility of the design day weather file, we compare simulation results of the peak load and load profile of a building obtained from the DOE-2.1E code and a specially developed load estimation program, PEAKLOAD. PEAKLOAD is developed using the transfer function method and ASHRAE databases. Comparative results are in good agreement, indicating that a design day thus selected can be used when quick answers are required and simulations using a TMY file cannot be easily done or justified.

}, keywords = {building simulation, design day, doe-2, peak load calculation, weather data}, doi = {10.1016/S0360-1323(98)00035-3}, author = {Tianzhen Hong and Siaw K. Chou and T.Y. Bong} } @proceedings {323, title = {A Model-Based Approach to the Commissioning of HVAC Systems}, year = {1997}, month = {08/1997}, address = {Brussles, Belgium}, author = {Richard A. Buswell and Philip Haves and Tim I. Salsbury} } @article {384, title = {Nanofluids for Heat Transfer Applications}, journal = {Annual Review of Heat Transfer}, volume = {14}, year = {1995}, pages = {255-275}, chapter = {255}, author = {Patrick E. Phelan and Ravi S. Prasher and Prajesh Bhattacharya} } @proceedings {331, title = {Model-Based Approaches to Fault Detection and Diagnosis in Air-Conditioning System}, year = {1994}, month = {12/1994}, address = {Li{\`e}ge, Belgium}, author = {Mourad Benouarets and Arthur L. Dexter and Richard S. Fargus and Philip Haves and Tim I. Salsbury and Jonathan A. Wright} } @proceedings {339, title = {Impacts of Climate Change}, year = {1992}, month = {05/1992}, address = {Solihull, England}, author = {Mike Hulme and Philip Haves and Boardman, B.} } @conference {55643, title = {Thermal Energy Storage System Sizing}, booktitle = {IBPSA Building Simulation {\textquoteright}89}, year = {1989}, month = {01/1989}, address = {Vancouver, BC, Canada}, url = {http://www.ibpsa.org/proceedings/BS1989/BS89_357_362.pdf}, author = {Dominique Dumortier and Ron C. Kammerud and Birdsall, Bruce E. and Brandt Andersson and Joseph H. Eto and William L. Carroll and Frederick C. Winkelmann} } @conference {55797, title = {The DOE-2 Computer Program for Thermal Simulation of Buildings}, booktitle = {American Institute of Physics (AIP)}, volume = {135}, number = {642}, year = {1985}, month = {01/1985}, publisher = {American Institute of Physics}, organization = {American Institute of Physics}, doi = {10.1063/1.35478}, author = {Birdsall, Bruce E. and Walter F. Buhl and Richard B. Curtis and Ender Erdem and Joseph Eto and James J. Hirsch and Karen H. Olson and Frederick C. Winkelmann} } @proceedings {55943, title = {New Features of the DOE-2.1c Energy Analysis Program}, year = {1985}, month = {01/1985}, publisher = {International Building Performance Simulation Association}, url = {http://www.ibpsa.org/proceedings/BS1985/BS85_195_200.pdf}, author = {Walter F. Buhl and Ender Erdem and Joseph H. Eto and James J. Hirsch and Frederick C. Winkelmann} } @conference {55945, title = {The DOE-2 Building Energy Analysis Program}, booktitle = {ASEAN Conference on Energy Conservation in Buildings}, year = {1984}, month = {05/1984}, address = {Singapore}, author = {Richard B. Curtis and Birdsall, Bruce E. and Walter F. Buhl and Ender Erdem and Joseph H. Eto and James J. Hirsch and Karen H. Olson and Frederick C. Winkelmann} } @conference {361, title = {Heat Loss Rates from Wetted Tilted Surfaces}, booktitle = {1st International Passive and Hybrid Cooling Conference, November 6-16, 1981}, series = {Passive Cooling}, year = {1981}, month = {11/1981}, publisher = {American Section of the International Solar Energy Society}, organization = {American Section of the International Solar Energy Society}, address = {Miami Beach, FL}, issn = {0895530333 9780895530332}, author = {Haines, R. and Philip Haves and Vollink, D.}, editor = {Arthur Bowen and Gene Clark} } @proceedings {367, title = {Heat Transfer in Passively Cooled Buildings}, year = {1980}, month = {07/1980}, address = {Orlando, FL}, author = {Philip Haves and Bently, D. and Gene Clark} } @article {370, title = {The Radio Structure of a Sample of 101 Quasars from the Parkes {\textpm}4{\textordmasculine} Survey}, journal = {Monthly Notices of the Royal Astronomical Society}, volume = {176}, year = {1976}, month = {08/1976}, pages = {275-306}, chapter = {275}, keywords = {Angular Distribution, Astronomical Catalogs, Quasars, Radio Emission, Radio Sources (Astronomy), Radio Spectra, Spectrum Analysis, Ultrahigh Frequencies}, author = {Michael Bentley and Philip Haves and Ralph E. Spencer and David Stannard} } @article {372, title = {High Resolution Observations of Extended Radio Sources at 1666 MHz}, journal = {Monthly Notices of the Royal Astronomical Society}, volume = {173}, year = {1975}, author = {Michael Bentley and Philip Haves and Ralph E. Spencer and David Stannard} } @article {374, title = {QSOs of High Redshift?}, journal = {Nature}, volume = {252}, year = {1974}, month = {11/1974}, pages = {209-210}, chapter = {209}, author = {Ian W.A. Browne and Michael Bentley and Philip Haves and Neil J. McEwan and Ralph E. Spencer and David Stannard} }