INTEGRATION AND INTEROPERABILITY OF BUILDING ENVELOPE INFORMATION AND ENERGY MODELING

Abstract

Different methods can be adopted in order to reduce the energy consumption in buildings, which contribute to about 40% of total annual energy consumption in the U.S. The following three major approaches were considered in this study: evaluation of buildings during the design phase and pre-construction phase, energy retrofit of existing buildings, and energy monitoring of buildings.

Building envelope components are among the elements in a building that can be improved or monitored for better energy performance in all three approaches mentioned above. Building envelope components considered in this study include both opaque and transparent components such as walls, roofs, floors, windows, and doors, which contribute to heat transfer in a building.

Building Energy Modeling (BEM) and analysis is one of the major tools contributing in energy conservation measures by providing users with data related to energy consumption of buildings. Therefore, improving different elements of BEM including the energy modeling process, obtaining outputs, and quality of outputs can be beneficial in energy conservation field.

This study is focused on improving these elements and the BEM process by expediting the whole process, making it more accurate by minimizing human interaction, and increasing the level of details of energy-related outputs. It can facilitate and increase the accuracy of

building’s energy evaluation during design phase, energy retrofit decision-making process, and energy monitoring.

A platform is developed to automate BEM, which provides users with detailed information on the amount of heat transfer through building envelope components. Building

Information Modeling (BIM) is adopted to facilitate the automation in modeling process. The developed tool is capable of 1) reading a BIM file, 2) correcting some information within the file, 3) automatically convert the BIM file to a file format, which is suitable for energy simulation, and 4) automatically perform energy simulation and generate text files containing detailed heat transfer data through every single building envelope component.

The first task is limited to gbXML file format, followed by a corrective tool developed using Python, which receives the BIM file and performs some corrections on data related to building envelope components such as doors and floors. Next, a code is developed in Ruby to use the pre-defined functions within OpenStudio source code in order to convert the gbXML file to IDF file. Since, this research is focused on building envelope, the issues and missing data related to other systems such as HVAC are resolved and added manually. The final task is carried out using modified source code of EnergyPlus, which receives the generated IDF file and performs energy simulation to generate five text files for walls, floors, roofs, windows, and doors. These files contain the detailed and fine-grained information on the amount of heat transfer through each component as opposed to accumulative data for each thermal zone or whole-house energy consumption.

Table of Contents

List of Figures …………………………………………………………………………………………………….. xi

List of Tables …………………………………………………………………………………………………… xvii

Technical Abbreviations …………………………………………………………………………………….. xix

Acknowledgments……………………………………………………………………………………………. xxiii

• Chapter 1. Introduction ………………………………………………………………………………….. 1
  • Energy Smart Homes ………………………………………………………………………………. 5
  • Building Envelope Energy Retrofit ……………………………………………………………. 6
  • Application of BIM in Energy Simulation ………………………………………………….. 7
• Chapter 2. Literature Review ………………………………………………………………………… 10
  • Energy Monitoring Systems ……………………………………………………………………. 11
  • Retrofit of Existing Homes …………………………………………………………………….. 24
  • Energy Modeling in Design Phase …………………………………………………………… 30
  • References ……………………………………………………………………………………………. 40
• Chapter 3. Methodology for Improving BEM Process and Outputs …………………… 50
  • Introduction ………………………………………………………………………………………….. 50
  • Objectives and Tasks Outline ………………………………………………………………….. 51
  • Further Explanation of the Tasks …………………………………………………………….. 52
    • Tasks for Objective #1 …………………………………………………………………….. 52
    • Tasks for Objective #2 …………………………………………………………………….. 53
  • Research Process Summary ……………………………………………………………………. 56
• Chapter 4. Energy Smart Homes …………………………………………………………………… 60

State of the Art Review of Energy Smart Homes ……………………………………………………. 61

• Abstract ……………………………………………………………………………………………….. 61
• Introduction ………………………………………………………………………………………….. 63
• The Very First Projects and Examples ……………………………………………………… 67
• Smart Homes Services …………………………………………………………………………… 69
• Smart Homes Components ……………………………………………………………………… 72
• Buildings, Projects, and Labs Focused on Smart Homes …………………………….. 74
• Challenges in Smart Home ……………………………………………………………………… 86
• Design Different Types of Energy Smart Homes ………………………………………. 87
  • Energy Monitoring Systems …………………………………………………………….. 95
  • Systems with Control Capabilities …………………………………………………… 100
  • Systems with Advanced Data Processing Capabilities ……………………….. 106
• Summary and Concluding Remarks ……………………………………………………….. 113
• References ………………………………………………………………………………………. 117 5) Chapter 5. Energy Retrofit of Buildings ……………………………………………………….. 166 Residential and Commercial Building Envelope Energy Retrofit: Innovative Measures

and Example Projects ………………………………………………………………………………………… 167

• Abstract ……………………………………………………………………………………………… 167
• Introduction ………………………………………………………………………………………… 168
• Materials and Systems in Envelope Energy Retrofit ………………………………… 172
  • Conventional retrofit measures ……………………………………………………….. 180
  • New retrofit measures ……………………………………………………………………. 183
• Example Retrofit Projects …………………………………………………………………….. 201
• Multiple Criteria and Proper Tools on Choosing Retrofit Measures …………… 212
• Numerical Study of Different Envelope Energy Retrofit …………………………… 216
  • Development of the Computer Model ……………………………………………… 217
  • Results of the Computer Modeling and Discussion ……………………………. 222
• Summary and Conclusions ……………………………………………………………………. 230
• References ………………………………………………………………………………………….. 233

• Chapter 6. Application of BIM in Energy Modeling ………………………………………. 244

Review of BIM’s application in energy simulation: tools, issues, and solutions ……….. 245

• Abstract ……………………………………………………………………………………………… 245
• Introduction ………………………………………………………………………………………… 247
• BEM tool’s Graphical User Interface (GUI) and energy simulation engine…. 254
• Types of BIM file schemas and their properties ………………………………………. 260
• Review of Identified Challenges and Issues in BBIP ……………………………….. 266
• Review of Identified Solutions Adopted by Researchers Related to BBIP ….. 273
• Review of three case studies in BBIP …………………………………………………….. 279
  • Modeling Process in Revit for Three Case Studies ……………………………. 282
  • Results of the Case Studies, Issues Related to the BBIP, and Suggested

Solutions ………………………………………………………………………………………………….. 287

• Developed gbXML corrective tool ………………………………………………….. 294

• Summary and Conclusion …………………………………………………………………….. 298
• References ………………………………………………………………………………………….. 302

• Chapter 7. Building Energy Performance Assessment Tool (BEPAT) ……………… 312

Development of a Platform for Building Energy Performance Assessment Tool (BEPAT)

for Energy Smart Homes and Design Optimization ………………………………………………. 313

• Abstract ……………………………………………………………………………………………… 313
• Introduction ………………………………………………………………………………………… 314
• Methodology for Developing and Validating BEPAT ………………………………. 320
• Computer Model and Validation Method ……………………………………………….. 328
• Results and Discussion …………………………………………………………………………. 333
• Summary and Conclusions ……………………………………………………………………. 340
• References ………………………………………………………………………………………….. 344

• Chapter 8. Automated Building Energy Modeling and Assessment Tool (ABEMAT)

350

Automated Building Energy Modeling and Assessment Tool (ABEMAT) ………………. 351

• Abstract ……………………………………………………………………………………………… 351
• Introduction ………………………………………………………………………………………… 352
• Methodology for Developing ABEMAT and Data Verification ………………… 358
  • First component of ABEMAT: gbXML corrective tool ……………………… 358
  • Second component of ABEMAT: gbXML to IDF converter ………………. 361
  • Third component of ABEMAT: IDF to fine-grained heat transfer outputs

364

• Methodology for Data Validation ……………………………………………………. 368

• Details of Modeling and Results of Data Validation ………………………………… 370
  • Comparison between Existing BEM Methods …………………………………… 371
  • Modeling a One-Story Residential Building for Data Verification ………. 375
  • The Outputs and Results of Data Verification …………………………………… 378
• Summary and Conclusions ……………………………………………………………………. 381
• References ………………………………………………………………………………………….. 3849)Chapter 9. Discussion, Summary, and Conclusion …………………………………………. 391
• Discussion ………………………………………………………………………………………….. 391
• Outcomes ……………………………………………………………………………………………. 394
• Research Contributions ………………………………………………………………………… 400
• Potential Future Researches ………………………………………………………………….. 402

Appendix A: Codes …………………………………………………………………………………………… 404

• Subroutines Added to EnergyPlus Source Code for Heat Transfer through

Windows ……………………………………………………………………………………………………… 404

Under the DataSurfaces module: …………………………………………………………………. 404

Under the DataSurfaces header: …………………………………………………………………… 404

Under OutputReportTabular module: …………………………………………………………… 404

• Subroutines Used for Other Components (Wall, Roof, Ceiling, Doors, and

IntMass): ……………………………………………………………………………………………………… 407

Under the HeatBalanceSurfaceManager module: …………………………………………… 407

Under the DataSurfaces header and .cc: ……………………………………………………….. 409

Chapter 1. Introduction

Buildings consume about 40% of total energy consumption in the U.S. Different correction or improvement measures can be applied to reduce the energy consumption in buildings. These measures can be applied during different phases of building life cycle such as design or use phase. For example, components such as building envelope can be designed more efficiently based on their energy performance. Moreover, energy retrofit of existing homes and energy consumption monitoring are two concepts related to use phase of buildings. Energy retrofit software programs and energy smart homes are among the emerging tools dedicated to these areas. The major contributions of this research are dedicated to these three areas mentioned above and shown in Figure 1-1.

Figure 1-1. Three major areas that can benefit from the outcomes of this research

Building energy modeling (BEM) and analysis is the major component in all such measures to reduce the energy consumption. Improved BEM process and outputs can contribute to more energy efficient design, optimized decision-making process in energy retrofit of existing buildings, and detailed and high quality information during energy monitoring in smart homes. Therefore, improving the BEM process can be focused on two major areas including the modeling process and quality of outputs, which are the focus of this research shown in Figure 1-2.

Figure 1-2. Two major areas in BEM and focus of improvement in this research

The modeling process can be improved by reducing manual interaction and automating the BEM process. An emerging tool that can contribute to this goal is Building Information Modeling (BIM), which can eliminate the need for reentering data and expedite the BEM process, resulting in less error vulnerability and more accuracy. However, multiple issues and challenges occur during the BIM-to-BEM process, which requires special attention and additional tools are required to resolve these issues. Existing tools still require manual interaction in many different stages of BIM-to-BEM process, since there are multiple components in this process including BIM tools, BIM files, BEM tools capable of reading BIM files, and multiple data transfer and file conversions. The main goal in BIM-to-BEM process can be developing a fully automated process with minimum manual interaction after the architectural model is developed.

Quality of outputs can be improved by providing fine-grained outputs related to every single component within a building contributing to energy consumption as opposed to accumulated outputs. For example, existing BEM tools only provide accumulated energy consumption with regard to a thermal zone or the whole house; however, these outputs can include fine-grained and detailed information on the amount of heat transfer through each building envelope component such as windows and walls. All three areas illustrated in Figure 1-1, can benefit from such information. Therefore, it can be beneficial if new tools are developed to provide such data in an easy, fast, and accurate way.

Developing a tool that can obtain a BIM file containing all the required data for energy simulation generated by a BIM tool, converting it to a file that can be read by BEM tools to perform energy analysis, and providing detailed outputs on the amount of heat transfer through building envelope components can be a great asset to automate the BEM process. The resulting detailed outputs can then contribute to the quality of building design tools, building’s energy retrofit tools, and energy monitoring in energy smart homes.

Reducing energy consumption in buildings can involve several tools in AEC industry and can be fulfilled through using multiple assets; however, picking a certain methodology help boiling down these options to limited number of tools and aspects of a building. For example, this goal can be reached through instrumenting a house with energy meters or smart outlets to measure the energy consumption of certain spaces and appliances in a building. In addition, the focus can be on electrical components, mechanical system, or building envelope. However, this study is focused on building energy simulation computer tools and building envelope components.

The multiple areas of study and research for this work include BEM in general, BIM, application of BIM in BEM, building envelope energy retrofit, decision-making process for energy retrofit, Computer-aided design (CAD) tools, BEM tools, energy smart homes, and energy monitoring tools. Hence, the following topical areas are selected for detailed study in order to identify state-of-the-art advances and related shortcomings and issues.

• Energy Smart homes
• Building envelope energy retrofit
• Application of BIM in energy simulation

A short introduction related to each topic is provided in this section and detailed literature review presented in the next section.

1.1 Energy Smart Homes

Several definitions are suggested by researchers for smart homes and covered in detail in the literature review section. Various capabilities can be attributed to smart homes including communication network, automatic control, remote control, and monitoring systems. Smart homes can be studied with regard to different aspects including their intended services and their components. Considering the services and components reviewed in the literature related to smart homes, the following definition can be considered as a good representative:

“A dwelling in which data related to home environment and its residents are obtained from sensors, electric appliances, or home gateway and transferred through a network of communication tools to monitoring device or execution unit to help decide on or execute proper actions called services. These services are provided either automatically or directly through a remote or central control system in order to facilitate or improve the residents’ daily lives”

One of the services considered for smart homes is dedicated to energy conservation aspect of buildings, and the smart homes equipped as such are referred to as energy smart homes. Energy smart homes are mainly focused on two aspects including control and monitoring capabilities. For example, control systems can automatically adjust the thermostat in a house to reach the comfort criteria. Monitoring capabilities, on the other hand, are dedicated to providing energy-related information for users, which can have incentive or decision-making effects in future energy consumption habits of residents. For example, energy meters can save energy consumption data and compare it to the average numbers within the neighborhood for incentive purposes [1] .

Several components can contribute to energy smart homes including the sensing unit, communication unit, processing unit, and control/execution unit. Review of multiple studies revealed that the processing unit, which collects information and sends proper outputs to either control or monitoring units, has room for improvements. This unit resembles the brain of the system and it can be equipped with new capabilities to perform more complicated computations such as energy simulation, in order to provide more detailed and accurate outputs.

This study is dedicated to similar aspect of energy smart homes and aims for developing a tool, which can equip the processing unit of energy smart homes with such capability to provide more detailed energy-related outputs in a fast, easy, and accurate way. Chapter 4, presents the results of the study on this area and explains the state-of-the-art technologies and shortcomings concerning energy smart homes.

1.2 Building Envelope Energy Retrofit

Energy retrofit is one of the major measures in reducing the existing building energy consumption, the majority of which can be considered to be due to mechanical systems, electrical components, and building envelope components. The effectiveness of different measures in energy retrofit has already been observed by researchers. Different measures can include replacing mechanical systems with more efficient products, replacing electrical systems such as appliances and lighting systems with more efficient options, and adding more insulation to the existing wall system, for example.

Multiple tools and components can contribute to this goal. Energy simulation tools can help in decision-making process by providing users with energy performance data of a building and identifying the components, which can be improved. Energy retrofit materials, products, and methods are also among the important components of building energy retrofit. Several conventional and new materials, technologies, and methods are studied by researchers and their effectiveness in reducing energy consumption is evaluated.

This study is focused on energy retrofit building envelope components such as walls, windows, roof, and floor. In order to identify the existing and innovative technologies and materials, a thorough study is conducted in Chapter 5, which can lead to a better understanding of tools and technologies related to building energy retrofit and the shortcomings.

1.3 Application of BIM in Energy Simulation

It is more convenient and less costly to improve and make changes in building design during the design or pre-construction phase of buildings, where computer models have high contribution. Such models can help evaluate the design prior to construction and provide users with different information depending on the focus of evaluation. Energy performance can be an important focus of these tools and evaluation process, which can be referred to as BEM.

BEM tools can provide users with different types of information such as whole-house energy consumption, consumption of different fuel types, energy-related costs, and energy consumption of different systems such as HVAC and lighting. These types of information can be used by engineers in order to change more energy intensive components and optimize the design. Therefore, it is important to make these types of information as accurate and detailed as possible. Moreover, facilitating the building energy modeling and analysis process can also be of great importance. Improving the BEM process can be focused on different aspects such as speed, convenience, and accuracy.

One of the tools, which can help in fulfilling this goal, is BIM, which is used in different areas of building construction industry such as facility management, architectural and structural design, and construction management. It can help to avoid reentering all the data at different stages in pre-construction phase, especially when different tools are adopted for modeling a building for different types of evaluation. Avoiding reentering the data can make the process faster and improve the accuracy by minimizing the manual interaction and human errors.

The BIM-to-BEM process is composed of multiple steps and components including the BIM authoring tools, BIM files, BEM tools, and converting BIM to BEM files. Many challenges and issues exist in these steps, and it is important to identify them to provide proper solutions. The BIM-to-BEM process is explained in Chapter 6, where the state-ofthe-art tools and methods in this field are reviewed and also the challenges and shortcomings identified. A comprehensive categorization is also suggested for different steps and components within the BIM-to-BEM interoperability process (BBIP). Also explained in Chapter 6 are the outcomes that can contribute to design of the computer tool developed in this study based on identification of the shortcomings and targeting their solution.

INTEGRATION AND INTEROPERABILITY OF BUILDING ENVELOPE INFORMATION AND ENERGY MODELING