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At least 1,081 records · Page 60

Commercial Building Prototypes Based on ANSI/ASHRAE/IES Standard 90.1-2019 Appendix G PRM: Technical Support Document

The two paths for documenting compliance with ANSI/ASHRAE/IES Standard 90.1 are the prescriptive path and the performance path. Beyond code programs and rating systems (for example, USGBC-LEED ) are primarily known to use a third path – the Appendix G Performance Rating Method. An update in the 2016 edition of Standard 90.1 approved the Appendix G Performance Rating System for code compliance, extending its application and allowing for greater consistency of modeling rules for code and beyond code building energy modeling. The Appendix G PRM provides rules for the development of whole building energy models of baseline and proposed models for calculating the “performance cost index target” value using the simulated energy results of the baseline and proposed models and the building performance factors published in Table 4.2.1.1 of the Standard. This report documents (1) the methodology used for development of the baseline and proposed energy models of the Pacific Northwest National Laboratory and U.S. Department of Energy commercial building prototypes using the Appendix G Performance Rating Method; and (2) the building performance factors that were calculated using those models.

97 MATHEMATICS AND COMPUTING↗

Sustain

Current building energy simulation technology requires excessive labor, time and expertise to create building energy models, excessive computational time for accurate simulations and difficulties with the interpretation of the results. These deficiencies can be ameliorated using modern graphical user interfaces and algorithms which take advantage of modern computer architectures and display capabilities. To prove this hypothesis, we developed an experimental test bed for building energy simulation. This novel test bed environment offers an easy-to-use interactive graphical interface, provides access to innovative simulation modules that run at accelerated computational speeds, and presents new graphics visualization methods to interpret simulation results. Our system offers the promise of dramatic ease of use in comparison with currently available building energy simulation tools. Its modular structure makes it suitable for early stage building design, as a research platform for the investigation of new simulation methods, and as a tool for teaching concepts of sustainable design. Improvements in the accuracy and execution speed of many of the simulation modules are based on the modification of advanced computer graphics rendering algorithms. Significant performance improvements are demonstrated in several computationally expensive energy simulation modules. The incorporation of these modern graphical techniques should advance the state of the art in the domain of whole building energy analysis and building performance simulation, particularly at the conceptual design stage when decisions have the greatest impact. More importantly, these better simulation tools will enable the transition from prescriptive to performative energy codes, resulting in better, more efficient designs for our future built environment.

Source record↗

Satellite Embedding-Based Population Imputation for Areas with Missing Building Footprint Data: A Computer Vision-Based Approach

High-resolution population modeling is important for supporting effective decision-making across diverse sectors. LandScan Mosaic generates population estimates at the level of individual buildings and aggregates them to 3 arc-second grids, and this approach performs well in regions where building footprint data are comprehensive and reliable. However, large portions of the globe still suffer from incomplete, sparse, or entirely missing building stock datasets, creating a structural limitation for strictly building-based population models. To address this research gap, this study proposes a computer vision-based framework that employs Google Earth Engine satellite embeddings and UNet, which allows us to directly impute grid-level population estimates in building-data-deficient areas. Applied to Taiwan as a case study, the framework achieved strong predictive performance with R$^{2}$ of 0.89, RMSE of 18.70, and MAE of 8.41, outperforming traditional machine learning approaches. Notably, the proposed framework effectively addressed building false-positive errors inherent in Global Human Settlement Layer (GHSL) data, correctly identifying uninhabited areas that were erroneously classified as populated. The framework also offers significant advantages for global population mapping, particularly in terms of scalability and temporal consistency, thereby extending the coverage and accuracy of high-resolution population products in data-scarce regions worldwide. Urban planners, decision makers, and related stakeholders can obtain granular population distributions to support more accurate and targeted infrastructure investment, service delivery, resource allocation, and risk assessment decisions.

97 MATHEMATICS AND COMPUTING↗

Building America Case Study: Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4, LaFayette, Georgia (CZ4), and Savannah, Georgia (CZ2)

The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk of condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.

Building America↗

Prototyping the BOPTEST Framework for Simulation-Based Testing of Advanced Control Strategies in Buildings

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.

Blum, David↗

Building fault detection and diagnostics: Achieved savings, and methods to evaluate algorithm performance

Fault detection and diagnosis (FDD) represents one of the most active areas of research and commercial product development in the buildings industry. This paper addresses two questions concerning FDD implementation and advancement 1) What are today's users of FDD saving and spending on the technology? 2) What methods and datasets can be used to evaluate and benchmark FDD algorithm performance? Relevant to the first question, 26 organizations that use FDD across a total 550 buildings and 97 M sf achieved median savings of 8%. Twenty-seven FDD users reported that the median base cost for FDD software, annual recurring software cost, and annual labor cost were $8, $2.7 and $8 per monitoring point, with a median implementation size of approximately 1300 points. To address the second question, this paper describes a systematic methodology for evaluating the performance of FDD algorithms, curates an initial test dataset of air handling unit (AHU) system faults, and completes a trial to demonstrate the evaluation process on three sample FDD algorithms. The work provided a first step toward a standard evaluation of different FDD technologies. Finally, it showed the test methodology is indeed scalable and repeatable, provided an understanding of the types of insights that can be gained from algorithm performance testing, and highlighted the priorities for further expanding the test dataset.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

The mechanism of eutectic modification by trace impurities

In the quest toward rational design of materials, establishing direct links between the attributes of microscopic building blocks and the macroscopic performance limits of the bulk structures they comprise is essential. Building blocks of concern to the field of crystallization are the impurities, foreign ingredients that are either deliberately added to or naturally present in the growth medium. While the role of impurities has been studied extensively in various materials systems, the inherent complexity of eutectic crystallization in the presence of trace, often metallic impurities ('eutectic modification') remains poorly understood. In particular, the origins behind the drastic microstructural changes observed upon modification are elusive. Herein, we employ an integrated imaging approach to shed light on the influence of trace metal impurities during the growth of an irregular (faceted-non-faceted) eutectic. Our dynamic and 3D synchrotron-based X-ray imaging results reveal the markedly different microstructural and, for the first time, topological properties of the eutectic constituents that arise upon modification, not fully predicted by the existing theories. Together with ex situ crystallographic characterization of the fully-solidified specimen, our multi-modal study provides a unified picture of eutectic modification: The impurities selectively alter the stacking sequence of the faceted phase, thereby inhibiting its steady-state growth. Consequently, the non-faceted phase advances deeper into the melt, eventually engulfing the faceted phase in its wake. We present a quantitative topological framework to rationalize these experimental observations.

36 MATERIALS SCIENCE↗

sympl (v. 0.4.0) and climt (v. 0.15.3) – towards a flexible framework for building model hierarchies in Python

sympl (System for Modelling Planets) andclimt (Climate Modelling and Diagnostics Toolkit) are anattempt to rethink climate modelling frameworks from the ground up. The aimis to use expressive data structures available in the scientific Pythonecosystem along with best practices in software design to allow scientists toeasily and reliably combine model components to represent the climate systemat a desired level of complexity and to enable users to fully understandwhat the model is doing. sympl is a framework which formulates the model in terms of astate that gets evolved forward in time or modified within a specifictime by well-defined components. sympl's design facilitates buildingmodels that are self-documenting, are highly interoperable, and providefine-grained control over model components and behaviour. symplcomponents contain all relevant information about the input they expect andoutput that they provide. Components are designed to be easily interchanged,even when they rely on different units or array configurations.sympl provides basic functions and objects which could be used inany type of Earth system model. climt is an Earth system modelling toolkit that contains scientificcomponents built using sympl base objects. These include both purePython components and wrapped Fortran libraries. climt providesfunctionality requiring model-specific assumptions, such as stateinitialization and grid configuration. climt's programming interfacedesigned to be easy to use and thus appealing to a wide audience. Model building, configuration and execution are performed through a Pythonscript (or Jupyter Notebook), enabling researchers to build an end-to-endPython-based pipeline along with popular Python data analysis andvisualization tools.

97 MATHEMATICS AND COMPUTING↗

Goddard Space Flight Center solar array missions, requirements and directions

The Goddard Space Flight Center (GSFC) develops and operates a wide variety of spacecraft for conducting NASA's communications, space science, and earth science missions. Some are 'in house' spacecraft for which the GSFC builds the spacecraft and performs all solar array design, analysis, integration, and test. Others are 'out of house' spacecraft for which an aerospace contractor builds the spacecraft and develops the solar array under direction from GSFC. The experience of developing flight solar arrays for numerous GSFC 'in house' and 'out of house' spacecraft has resulted in an understanding of solar array requirements for many different applications. This presentation will review those solar array requirements that are common to most GSFC spacecraft. Solar array technologies will be discussed that are currently under development and that could be useful to future GSFC spacecraft.

Gaddy, Edward↗

Goddard Space Flight Center Solar Array Missions, Requirements and Directions

The Goddard Space Flight Center (GSFC) develops and operates a wide variety of spacecraft for conducting NASA's communications, space science, and earth science missions. Some are "in house" spacecraft for which the GSFC builds the spacecraft and performs all solar array design, analysis, integration, and test. Others are "out of house" spacecraft for which an aerospace contractor builds the spacecraft and develops the solar array under direction from GSFC. The experience of developing flight solar arrays for numerous GSFC "in house" and "out of house" spacecraft has resulted in an understanding of solar array requirements for many different applications. This presentation will review those solar array requirements that are common to most GSFC spacecraft. Solar array technologies will be discussed that are currently under development and that could be useful to future GSFC spacecraft.

Gaddy, Edward↗

mdtmFTP

To address the high-performance challenges of data transfer in big data era, we research, develop, and implement mdtmFTP: a High-performance Data Transfer Tool in Bigdata Era. DOE’s Advanced Scientific Computing Research (ASCR) office has funded Fermilab and Brookhaven National Laboratory to collaboratively work on the Multicore-Aware Data Transfer Middleware (MDTM) project. MDTM aims to accelerate data movement toolkits on multicore systems. mdtmFTP is the latest outcome of this continued research effort. mdtmFTP is a high-performance data transfer tool that builds upon the MDTM middleware. Initial tests show that mdtmFTP performs better than existing data transfer tools

Zhang, L.↗

Dynamic Thermal Performance Analysis of PCM Products Used for Energy Efficiency and Internal Climate Control in Buildings

PCMs are attractive for the future generation of buildings, where energy efficiency targets and thermal comfort expectations are increasingly prioritized. Experimental analysis of local thermal processes in these dynamic components and whole-building energy consumption predictions are essential for the proper implementation of PCMs in buildings. This paper discusses the experimental analysis of the thermophysical characteristics of both a latent heat storage material (PCM) and a product containing this PCM. The prototype product under investigation is a panelized PCM technology containing inorganic, salt-hydrate-based PCM. The thermal analysis includes studies of melting and freezing temperatures, enthalpy changes during phase change processes, nucleation intensity, sub-cooling effects, and PCM stability. The PCM’s stability is also investigated, as is the ability of PCM products to control local temperatures and peak load transmission times. Two inorganic PCM formulations based on calcium chloride hexahydrate (CaCl 2 .6H 2 O) were prepared and tested in laboratory conditions. Material-scale testing results were compared with outcomes from the system-scale analysis, using both laboratory test methods as well as field exposure in test huts. This work demonstrates that PCM technologies used in buildings can effectively control both the magnitude of thermal storage capacity as well as the time of the peak thermal load. It was found that commonly used material-scale testing methods may not always be beneficial in assessing the dynamic thermal performance characteristics of building technologies containing PCMs.

42 ENGINEERING↗

Energy Modeling for the Artisan Food Center

The Artisan Food Center is a 6912 sq.ft food processing plant located in Dayton, Washington. PNNL was contacted by Strecker Engineering to assist with the building’s energy analysis as a part of the project’s U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) submittal requirements. The project is aiming for LEED Silver certification, one of the prerequisites to which is a whole building energy model to demonstrate compliance with American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) 90.1 2007 Appendix G, Performance Rating Method. The building incorporates a number of energy efficiency measures as part of its design and the energy analysis aimed at providing Strecker Engineering with the know-how of developing an energy model for the project as well as an estimate of energy savings of the proposed design over the baseline design, which could be used to document points in the LEED documentation. This report documents the ASHRAE 90.1 2007 baseline model design, the proposed model design, the modeling assumptions and procedures as well as the energy savings results in order to inform the Strecker Engineering team on a possible whole building energy model.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

The relative importance of building design parameters in reducing energy use and sensible heat release from buildings in light of forecasted future weather data and building coverage ratio

Buildings typically have a 60-to-75-year lifespan before they require significant maintenance or modifications. However, most builders evaluate the performance of their new buildings using whole-building energy simulation tools based on the current typical meteorological year (TMY) file or actual meteorological year. The energy use consumption and sensible heat release pattern observed from buildings could potentially change based on shifting global climates. Therefore, the recommended energy-efficiency design parameters might also change during these periods. In this study, we evaluate the role of different building design parameters, such as material reflectivity, HVAC COP, and insulation values, on building energy usage and sensible heat release from buildings with different building coverage ratios (BCR), based on the current and future weather file TMY (fTMY) for the middle of the century (2040–2060). The role of sensible heat release from buildings is not accounted for accurately while estimating building energy usage in most whole-building energy simulations. The study conducts a series of whole-building energy simulation analyses using EnergyPlus to evaluate the role of different design parameters based on TMY and fTMY weather conditions. The analysis is conducted for two hot desert climatic cities: Phoenix (USA) and Abu Dhabi (UAE). The results show that, for the base case in a future climate, the sensible heat release is reduced by an average of 30% due to the reduced delta T between the surface and ambient air. Further, the results show an increase in total energy consumption by 5% annually. The results also show that, for buildings with traditional coatings, shorter buildings release more heat than taller buildings. On the other hand, for buildings with reflective paints, shorter buildings release less heat than taller buildings. The findings from this study can be used by policymakers, utility companies, and builders to better understand the relative role of different building design parameters while constructing new and retrofitting existing buildings.

Alhazmi, Mansour [King Fahd University of Petroleu↗

Federal Government Energy Management and Conservation Programs (Fiscal Year 2008)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Annual Report on Federal Government Energy Management and Conservation Programs (Fiscal Year 2010)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Annual Report on Federal Government Energy Management and Conservation Programs (Fiscal Year 2011)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Annual Report on Federal Government Energy Management and Conservation Programs (Fiscal Year 2012)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗