Abstract: A software tool that automates the analysis of functional tests for air-handling units is described. The tool compares the performance observed during manual tests with the performance predicted by simple models of the components under test that are configured using design information and catalog data. Significant differences between observed and expected performance indicate the presence of faults. Fault diagnosis is performed by analyzing the variation of these differences with operating point using expert rules and fuzzy inferencing.

The tool has a convenient user interface to facilitate manual entry of measurements made during a test. A graphical display compares the measured and expected performance, highlighting significant differences that indicate the presence of faults. The tool is designed to be used by commissioning providers conducting functional tests as part of either new building commissioning or retro-commissioning, as well as by building owners and operators conducting routine tests to check the performance of their HVAC systems. The paper describes the input data requirements of the tool, the software structure, the graphical interface, and summarizes the development and testing process used.

Abstract: The paper describes a model-based approach to automated functional testing at the component level and presents results from preliminary field testing of a prototype software tool that implements the method. The method is based on an integrated life-cycIe approach to HVAC commissioning and performance monitoring. The tool uses component-level HVAC equipment models implemented in an equation-based simulation environment. When used for comissioning, each model is configured using design information and component manufacturers" data. Once an acceptable functional test has been performed, the model is fine-tuned to match the actual performance of the equipment by using data measured during the functional test. The fine-tuned model is then used in routine operation for on-line monitoring and fault detection. The paper describes the method and reports test results from HVAC secondary systems in a commercial building and an experimental facility.

Abstract: A hybrid simulation environment for controls testing and training is described. A real-time simulation of a building and HVAC system is coupled to a real building control system using a hardware interface. A prototype has been constructed and tested in which the dynamic performance of both the HVAC equipment and the building envelope is simulated using SPARK (Simulation Problem Analysis and Research Kernel). A low cost hardware interface between the simulation and the real control system is implemented using plug-in analog-to-digital and digital-to-analog cards in a personal computer. The design and implementation of the hardware interface in SPARK are described. The development of a variant of this environment that uses a derivative of EnergyPlus to test the implementation of a natural ventilation control strategy in real control hardware is also described.

Various applications of the hybrid simulation environment are briefly described, including the development of control algorithms and strategies, control system product testing and the pre-commissioning of building control system installations. The application to the education and training of building operators and HVAC service technicians is discussed in more detail, including the development of a community college curriculum that includes the use of the hybrid simulation environment to teach both control system configuration and HVAC troubleshooting.

Abstract: The design for the new Federal Building in San Francisco includes an office tower that is to be naturally ventilated. Each floor is designed to be cross-ventilated, through upper windows that are controlled by the building management system (BMS). Users have control over lower windows, which can be as much as 50% of the total openable area. There are significant differences in the performance and the control of the windward and leeward sides of the building, and separate monitoring and control strategies are determined for each side. The performance and control of the building has been designed and tested using a modified version of EnergyPlus.

Results from studies with EnergyPlus and CFD are used in designing the control strategy. EnergyPlus was extended to model a simplified version of the airflow pattern determined using CFD. Wind-driven cross-ventilation produces a main jet through the upper openings of the building, across the ceiling from the windward to the leeward side. Below this jet, the occupied regions are subject to a recirculating airflow. Results show that temperatures within the building are predicted to be satisfactory, provided a suitable control strategy is implemented uses night cooling in periods of hot weather.

The control strategy has 10 window opening modes. EnergyPlus was extended to simulate the effects of these modes, and to assess the effects of different forms of user behavior. The results show how user behavior can significantly influence the building performance.

(Note: PDF contains both LBNL-56010 & LBNL-56010 Conf.)

Abstract: The design for the new Federal Building for San Francisco includes an office tower that is to be naturally ventilated. Each floor is designed to be cross-ventilated, through upper windows that are controlled by the building management system. Users have control over lower level windows, which can be as much as 50% of the total openable area. There are significant differences in the performance and the control of the windward and leeward sides of the building, and separate monitoring and control strategies are determined for each side. The performance and control of the building has been designed and tested using a modified version of EnergyPlus. Results from studies with EnergyPlus and computational fluid dynamics are used in designing the control strategy. Wind-driven cross-ventilation produces a main jet through the upper openings of the building, across the ceiling from the windward to the leeward side. Below this jet, the occupied regions are subject to a recirculating airflow. Results show that temperatures within the building are predicted to be satisfactory, provided a suitable control strategy is implemented that uses night cooling in periods of hot weather. The control strategy has 10 window opening modes. EnergyPlus was extended to simulate the effects of these modes, and to assess the effects of different forms of user behaviour. The results show how user behaviour can significantly influence the building performance.

(Note: PDF contains both LBNL-56010 & LBNL-56010 Conf.)

Abstract: A new guidance concept is presented, which encourages third parties, like educators, to provide additional, comprehensive information to users of highly complex (e.g. simulation-) software, helping them to flatten the steep learning curve by understanding the impact of decisions made during the input/design process.

Abstract: This paper is about the merging of two software applications that allows building decision makers to consider code compliance and to use performance simulation tools from the early, schematic phases of building design. By making the capabilities of a code compliance tool available at the early schematic phases of building design, the hope and expectation is that users will use this software to address the mandatory code compliance issues and thus have an opportunity to address other performance issues as well.

Abstract: A description of the in-progress design of a new Federal Office Building for San Francisco is used to illustrate a number of issues arising in the design of large, naturally ventilated office buildings. These issues include the need for an integrated approach to design involving the architects, mechanical and structural engineers, lighting designers and specialist simulation modelers. In particular, the use of natural ventilation, and the avoidance of air-conditioning, depends on the high degree of exposed thermal mass made possible by the structural scheme and by the minimization of solar heat gains while maintaining the good daylighting that results from optimization of the facade. Another issue was the need for a radical change in interior space planning in order to enhance the natural ventilation; all the individual enclosed offices are located along the central spine of each floorplate rather than at the perimeter. The role of integration in deterring the undermining of the design through value engineering is discussed. The comfort criteria for the building were established based on the recent extension to the ASHRAE comfort standard based on the adaptive model for naturally ventilated buildings. The building energy simulation program EnergyPlus was used to compare the performance of different natural ventilation strategies. The results indicate that, in the San Francisco climate, wind-driven ventilation provides sufficient nocturnal cooling to maintain comfortable conditions and that external chimneys do not provide significant additional ventilation at times when it when it would be beneficial.

Abstract: This paper is about a web-based virtual lighting simulator, which is intended to allow architects and lighting designers to quickly assess the effect of key parameters on the daylighting and lighting performance in various space types. The virtual lighting simulator consists of a web-based interface that allows navigation through a large database of images and data, which were generated through parametric lighting simulations. At its current form, the virtual lighting simulator has two main modules, one for daylighting and one for electric lighting.

The daylighting module includes images and data for a small office space, varying most key daylighting parameters, such as window size and orientation, glazing type, surface reflectance, sky conditions, time of the year, etc. The electric lighting module includes images and data for five space types (classroom, small office, large open office, warehouse and small retail), varying key lighting parameters, such as the electric lighting system, surface reflectance, dimming/switching, etc.

The computed images include perspectives and plans and are displayed in various formats to support qualitative as well as quantitative assessment. The quantitative information is in the form of iso-contour lines superimposed on the images, as well as false color images and statistical information on work plane illuminance. The qualitative information includes images that are adjusted to account for the sensitivity and adaptation of the human eye. The paper also includes a section on the major technical issues and their resolution.

Abstract: An appraisal of the potential performance of different Low Energy Cooling (LEC) systems in non-residential 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:

- air-side indirect and indirect/direct evaporative pre-cooling

- cool beams

- displacement ventilation

sResults 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.

Abstract: The need for proper consideration of energy-related performance aspects during building design has been identified since the energy crises of the 1970s. However, energy performance is still considered in a very small fraction of building projects, mainly because proper consideration is very expensive. It requires the use of computational software tools, which are not easy to learn and are time-consuming to use.

Several attempts have been made to facilitate the use of energy simulation tools, but none has brought a significant increase in the consideration of energy performance. Energy related performance criteria are still considered only in a small fraction of buildings and, in most cases, after most of the building design is complete.

This paper is focused on the main barriers in properly considering energy-related performance aspects in building decisions, which range from sociopolitical, to technical. The paper includes consideration of issues related to the general interest of the building industry in energy performance and environmental impact, current practice trends, modeling capabilities and performance of tools, compatibility of computational models and availability of data.

Finally, a strategy for government-industry collaboration towards removing the barriers is presented, along with the main issues that need to be resolved towards potential implementation.

Abstract: Design studios and building science courses have been conducted independent of each other, mainly due to a lack of tools that allow quick and easy consideration of building science criteria, such as comfort and energy requirements, during the design process. Existing tools are not user-friendly and their use requires significant effort in gaining familiarity with the input requirements, understanding the modeling assumptions and interpreting the output. This paper is about the Building Design Advisor (BDA), an evolving computer-based tool intended to bridge the gap between design studios and building science considerations by addressing the above-mentioned limitations of existing tools. BDA allows automatic preparation of input files to multiple simulation tools while the user is working in a CAD environment. BDA automatically activates the relevant simulation tools when the user selects performance parameters to be computed and provides the results in a graphical form, allowing comparison of multiple design options with respect to multiple performance criteria. The paper includes considerations for the use of the BDA in the design studio and ends with a description of the current development efforts and future plans.

Abstract: Lighting design involves the consideration of multiple performance criteria, from the earliest stages of conceptual design, through various stages of controls and operation in a project"s life cycle. These criteria include a) the quantitative analysis of illuminance and luminance distribution due to daylighting and electric lighting, b) qualitative analysis of the lighting design with photometrically accurate renderings of the designed environment, c) analysis of energy implications of daylighting and electric lighting design and operation, and d) analysis of control strategies and sensor placement for maximizing energy savings from lighting control while providing visual comfort.

In this paper we describe the development of an integrated decision-making environment that brings together several different tools, and provides the data management and process control required for a multi-criterion support of the design and operation of daylighting and electric lighting systems. The result is a powerful design and decision-making environment to meet the diverse and evolving needs of lighting designers and operators.

Abstract: There is currently no effective combination of interoperable design tools to cover all critical aspects of the HVAC design process. Existing design tools are separately available, but require expertise and operating time that is beyond the scope of a normal design project. For example, energy analysis and computational fluid dynamics (CFD) tools are not used in practical design, leading to poor indoor air quality and/or unnecessary energy consumption in buildings.sA prototype integrated software tool for demonstration, process mapping and proof-of-concept purposes was developed under a new international, Finland/USA jointly funded development project Bild-IT. Individual design tools were simplified and adapted to specific applications and also integrated so that they can be used in a timely and effective manner by the designer. The core of the prototype linked together an architectural CAD system, a 3D space model, a CFD program and a building energy simulation program and it utilises real product data from manufacturer?s software. Also the complex building design, construction, maintenance and retrofit processes were mapped to get a template for the structure of the integrated design tool.

Abstract: In this paper we address the issue of building data schema evolution in integrated simulation environments, as seen from the perspective of incorporating LCA tools within these environments. First we describe the key features of an integrated simulation environment designed for expandability, focusing on a) the mechanism for the expansion of the integrated environment, and b) its overall system architecture that allows processes and data to be added to the system without modifications or restructuring of existing code.

We then focus on how the data schema allows the inclusion and maintenance of specialized construction objects bearing LCA data. Finally, we discuss various integration issues that arise from modeling capabilities and idiosyncrasies of individual simulation and analysis tools.

Abstract: The use of daylight for the illumination of building interiors has the potential to enhance the quality of the environment while providing opportunities to save energy by replacing or supplementing electric lighting. Moreover, it has the potential to reduce heating and cooling loads, which offer additional energy saving opportunities, as well as reductions in HVAC equipment sizing and cost. All of these benefits, however, assume proper use of daylighting strategies and technologies, whose performance depends on the context of their application. On the other hand, improper use can have significant negative effects on both comfort and energy requirements, such as increased glare and cooling loads. To ensure proper use, designers need tools that model the dynamic nature of daylight and accurately predict performance with respect to a multitude of performance criteria, extending beyond comfort and energy to include aesthetics, cost, security, safety, etc.

Abstract: To make decisions, building designers need to predict and assess the performance of their ideas with respect to various criteria, such as comfort, esthetics, energy, environmental impact, economics, etc. Performance prediction with respect to environmental impact requires complicated models and massive computations, which are usually possible only through computer-based tools. This paper focuses on the use of,computer-based tools for predicting and assessing building performance with respect to environmental impact criteria for the design of green.buildings. It contains analyses of green performance prediction/assessment and descriptions of available tools, along with discussions on their use by different types of users. Finally, it includes analyses of the cost and benefits of green performance prediction and assessment.

Abstract: Decisions throughout the life cycle of a building, from design through construction and commissioning to operation and demolition, require the involvement of multiple interested parties (e.g., architects, engineers, owners, occupants and facility managers). The performance of alternative designs and courses of action must be assessed with respect to multiple performance criteria, such as comfort, aesthetics, energy, cost and environmental impact. Several stand-alone computer tools are currently available that address specific performance issues during various stages of a building"s life cycle. Some of these tools support collaboration by providing means for synchronous and asynchronous communications, performance simulations, and monitoring of a variety of performance parameters involved in decisions about a building during building operation. However, these tools are not linked in any way, so significant work is required to maintain and distribute information to all parties.

In this paper we describe a software model that provides the data management and process control required for collaborative decision making throughout a building"s life cycle. The requirements for the model are delineated addressing data and process needs for decision making at different stages of a building"s life cycle. The software model meets these requirements and allows addition of any number of processes and support databases over time. What makes the model infinitely expandable is that it is a very generic conceptualization (or abstraction) of processes as relations among data. The software model supports multiple concurrent users, and facilitates discussion and debate leading to decision making. The software allows users to define rules and functions for automating tasks and alerting all participants to issues that need attention. It supports management of simulated as well as real data and continuously generates information useful for improving performance prediction and understanding of the effects of proposed technologies and strategies.

Abstract: This paper is about research and development efforts on the use of information technologies to assist in building design decisions. Theoretical models of the design and decision-making processes are described along with their implementation for the development of the Building Design Advisor (BDA), a software environment designed to facilitate informed decisions from the early schematic phases of building design to the detailed specification of building components and systems. To do that, the BDA supports the integrated, concurrent use of multiple simulation tools and databases, and makes their output available in forms that support multicriterion judgment. The BDA data structures and algorithms for data management and process control are presented along with its graphical user interface and the simulation processes linked to its initial version. Finally, plans for future work are described, aimed at the expansion of the BDA software to link to additional tools and databases, and address the data needs of the whole building life cycle, from design, through contruction and commissioning, to operation and demolition.

Abstract: The use of daylight for the illumination of building interiors has the potential to enhance the quality of the environment while providing opportunities to save energy by replacing or supplementing electric lighting. Moreover, it has the potential to reduce heating and cooling loads, which offer additional energy saving opportunities as well as reductions in HVAC equipment sizing and cost. All of these benefits, however, assume proper use of daylighting strategies and technologies, whose performance depends on the context of their application. On the other hand, improper use can have significant negative effects on both comfort and energy requirements, such as increased glare and cooling loads. To ensure proper use, designers need tools that model the dynamic nature of daylight and accurately predict performance with respect to all performance aspects affected, which extend beyond comfort and energy to include esthetics, cost, security, safety, etc.

Research and development efforts during the last twenty-five years have resulted in a number of computer-based tools, with varying degrees of modeling capabilities and prediction accuracy. Most of these tools, however, especially those with extended modeling capabilities and high degree of accuracy, are very expensive to use. In addition to extensive training, they require time-consuming preparation of input that describes the building and its context, and significant processing of the output to evaluate and analyze the predicted performance. In this paper, we present two software tools that will eventually contribute to faster and better evaluation of daylighting strategies and technologies.

The first tool is the Building Design Advisor (BDA), which facilitates the use of multiple simulation tools by automating the preparation of the required input and integrating the output in graphic displays that support multi-criterion, simultaneous evaluation of multiple design options. Through a smart default value mechanism, it allows use of simulation tools from the early, schematic phases of building design. Moreover, through links to a Web-based case studies database of actual buildings, it facilitates formulation of realistic performance targets and evaluation of alternative design schemes. The 1.0 version of the BDA is linked to two simplified simulation tools, one for the prediction of daylight work-plane illuminance and glare index in rectangular spaces, and the other for the prediction of energy requirements by end use and energy source, which also includes HVAC auto-sizing.

The second tool is the latest release of the RADIANCE day/lighting simulation and rendering program, which computes luminance and illuminance values for arbitrary space and fenestration configurations. In addition, RADIANCE produces photo-accurate images of the modeled environment. The added functionality in the new release supports post-processing of the computed images to make them closely correspond to the dynamic exposure and tone mapping of the human eye. It also supports the generation of animated walk-through and time sequences.

Our plans for the future include the development of links between a PC version of RADIANCE and the BDA. With the BDA also being linked to the DOE-2 building energy simulation program, we expect to integrate the use of simplified and sophisticated tools to address daylighting from the early, schematic phases of building design through the detailed specifications of building components and systems.

Abstract: A new, comprehensive design theory is presented, applicable to all design domains such as engineering and industrial design, architecture, city and regional planning, and, in general, any goal-oriented activity that involves decision making. The A new, comprehensive design theory is presented, applicable to all design domains such as engineering and industrial design, architecture, city and regional planning, and, in general, any goal-oriented activity that involves decision making. The design process is analyzed into fundamental activities that are characterized with respect to the nature of knowledge requirements and the degree to which they can be specified and delegated to others, in general, and to computers in particular.

Throughout the history of research in design theories and methods, from the 1940s with operations research and optimization, through the 1960s with the characterization of design problems as wicked, or ill-defined, design has been understood as a rational activity, that is thinking before acting. The new theory presented in this paper suggests that design is thinking and feeling while acting, supporting the position that design is only partially rational. Intelligence, natural or artificial, is only one of two requirements for design, the other being emotions. Design decisions are only partially inferred, that is, they are not entirely the product of reasoning. Rather, design decisions are based on judgment that requires the notion of good and bad, which is attributed to feelings, rather than thoughts.

The presentation of the design theory extends to the implications associated with the limits of intelligence in design, which, in-turn, become constraints on the potential role of computers in design. Many of the current development efforts in computer-aided design violate these constraints, especially in the implementation of expert systems and multi criterion evaluation models. These violations are identified and discussed in detail. Finally, specific areas for further research and development in computer-aided design are presented and discussed.design process is analyzed into fundamental activities that are characterized with respect to the nature of knowledge requirements and the degree to which they can be specified and delegated to others, in general, and to computers in particular. Throughout the history of research in design theories and methods, from the 1940s with operations research and optimization, through the 1960s with the characterization of design problems as "wicked," or "ill-defined," design has been understood as a rational activity, that is "thinking before acting." The new theory presented in this paper suggests that design is "thinking and feeling while acting," supporting the position that design is only partially rational. Intelligence, "natural" or "artificial," is only one of two requirements for design, the other being emotions. Design decisions are only partially inferred, that is, they are not entirely the product of reasoning. Rather, design decisions are based on judgment that requires the notion of "good" and "bad," which is attributed to feelings, rather than thoughts.

The presentation of the design theory extends to the implications associated with the limits of intelligence in design, which, in turn, become constraints on the potential role of computers in design. Many of the current development efforts in computer-aided design violate these constraints, especially in the implementation of expert systems and multi-criterion evaluation models. These violations are identified and discussed in detail. Finally, specific areas for further research and development in computer-aided design are presented and discussed.