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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 433 records · Page 24

NorthernSTAR 1.5-Story Demonstration House of Cold Climate Solutions for Affordable Housing

This is a NorthernSTAR renovation project for Urban Homeworks incorporating installation of a combination space and water heater, Overcoat insulation retrofit on the roof, and Excavationless foundation insulation retrofit. STRUCTURE - 1401 North 16th Ave Minneapolis, MN 55411 Various groups from the affordable housing industry have consulted with the University of Minnesota's Cold Climate Housing Program to solve persistent energy and health-related problems such as ice dams, high energy bills, and mold/moisture issues-especially in complicated house types such as 1.5-story homes in cold climates. The NorthernSTAR Building America Partnership has completed multiple research projects on high-performance measures applied during renovation of single-family homes that could help the affordable housing industry address performance concerns. This demonstration project is an example of three high-performance measures applied to one house in Minneapolis, Minnesota. The selected vacant home was completely renovated by Urban Homeworks (UHW), which is a nonprofit housing partner, with the intent of selling the home to a low-income family. The renovation included the addition of the three advanced-performance technologies that were applied to the overall scope of the project. Single-family homes in urban areas that are available for renovation by nonprofit developers are often in need of repair. Budgeting has historically focused on improving homes to meet basic housing standards. A rising interest in the long-term impact of homeownership has introduced the need to balance basic needs with home performance. The goal of this demonstration project was to help UHW and other nonprofit developers become familiar with three U.S. Department of Energy Building America performance measures-including the installation processes, impacts, and benefits of each. To maximize efficiency of application and to address budget issues, the NorthernSTAR team worked with UHW to identify ways to use volunteers and construction training programs to install the measures. An open invitation to visit the job site was provided to other nonprofit developers and support teams to encourage dialog about the systems during live installation.

affordable housing↗

Greenbuilt Construction Energy Efficiency Retrofit House Demonstration - Sacramento

One of the homes that was part of Sacramento Municipal Utility District's (SMUD) Energy Efficiency Retrofit Demonstration (EERD) project was a 1980's era home in Fair Oaks, California, referred to as the Greenbuilt house, as Greenbuilt Construction completed the retrofit of the home. The home underwent an extensive energy efficiency retrofit with a goal of achieving a 50% reduction in energy use to demonstrate the potential for other builders and homeowners in the area. The retrofit measures included installing: ENERGY STAR appliances high efficiency light roof radiant barrier additional ceiling and wall insulation double-pane, low-e windows external motorized shading and solar tubes a 16 SEER/9.75 HSPF heat pump improved ducts a whole-house fan a heat pump water heater (HPWH) integrated collector storage solar water heater (ICS SWH) and 3.2 kW of PV. In addition, the home was air sealed to reduce infiltration. Researchers from the National Renewable Energy Laboratory (NREL) performed short-term tests on the major systems installed as part of the retrofit to ensure that they were performing as expected. The systems evaluated included the space conditioning heat pump, the air handler and ducts, the HPWH, the ICS SWH, and the PV array. Some ducts were untwisted after testing revealed that two rooms were not getting sufficient airflow. Afterwards, all systems were performing as expected. In addition to testing to confirm adequate performance of all new systems, NREL was given the opportunity to use the Greenbuilt house as a laboratory house for a year. The space conditioning system and home water systems were subjected to a series of tests to determine optimal control strategies for lowering energy consumption and reducing peak (4:00-7:00 p.m.) energy consumption during the summer. The different cooling strategies considered included two different precooling schedules, drawing the external shades during the day and using the whole-house fan at night, and combinations of those. The most effective strategy for reducing overall energy consumption was the use of external shades, which cut the daily cooling load by 34% and reduced the energy use during peak hours by 40%. The different precooling strategies eliminated the peak load entirely but actually increased daily cooling energy use. The use of shades and the advanced precooling strategy increased the daily energy use by 5% but eliminated all peak use and maintained a comfortable home. These results were verified over the entire summer using an Energy Plus model of the home. The hot water system was tested in two configurations: the HPWH alone and the ICS solar water heater paired with the HPWH. Six hot water draw profiles, varying in terms of daily hot water volume, time of day for hot water use, and the duration of the draws, were imposed on the hot water system to test their effects on performance. When operating alone in the summer, the HPWH operated with a COP around 2.2, except for a draw that used a quarter of the averaged daily hot water usage, which had an average COP of 1.6. The combination of ICS and HPWH resulted in larger COPs, but also more variability depending on the draw profile. The standard, hourly draw profile produced the highest COP of 6.4. The quarter volume draw profile had the lowest COP of 2.8 for the combined system. Relative to a standard electric water heater, the HPWH operating alone reduced the peak load by 56% and the combined ICS and HPWH system completely eliminated the peak load.

air sealing↗

NorthernStar Zero Energy Ready Homes

This is a repository for all NorthernSTAR Zero Energy Ready certified homes. Amaris Homes Model Home - St. Paul, MN 55110 Description: Model home completed September 2013 The DOE Zero Energy Ready Home Case Study looks to study and eventually design zero net energy homes in cold weather climates. These zero net energy homes are referred to as challenge homes. For this challenge home, Amaris Homes is working with the DOE in St. Paul, Minnesota. The household located at MN 55110 acts as the Amaris Challenge Home Test. The resources include technical drawings including siding, roofing and Windows. Christian Builders Challenge Home - House Count: 1 - Otsego, MN 55374 Need pictures from builder; This home actually narrowly missed certification under DOE Net Zero Energy Ready Homes. Need building plans and project summary from builder. DESIGN AND STRUCTURE - Amaris Homes - House Count: 7 Stillwater, MN 55082; Vadnais Heights, MN 55127; Bloomington, MN 55437; Apple Valley, MN 55124; White Bear Lake, MN 55110; Mounds View, MN 55112; Midland, MI 48642; DOE Zero Energy Ready Homes

Array↗

Empirical Modeling of Direct Expansion (DX) Cooling System for Multiple Research Use Cases

This study provides a general procedure to generate a direct expansion (DX) cooling coil system for a roof top unit (RTU), which is a typical heating ventilation and air-conditioning (HVAC) system for commercial buildings in the United States. Experimental data from a full-scale unoccupied 2-story commercial building is used for the HVAC modeling. The regression for identifying the model coefficients was carried out with multiple stages, and the results were validated with measured data. The model’s applicability was evaluated with multiple case studies, including a building energy simulation (BES) program validation, model-based predictive control (MPC), and fault diagnostics and detection (FDD).

42 ENGINEERING↗

ACCELERATED PILOT PROJECT FOR U CANYON DEMOLITION

At the U.S. Department of Energy's Hanford Site in southeast Washington State, CH2M HILL Plateau Remediation Company (CH2M HILL) is underway on a first-of-a-kind project with the decommissioning and demolition of the U Canyon. Following the U.S. Environmental Protection Agency's Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) Record of Decision for the final remediation of the canyon, CH2M HILL is combining old and new technology and techniques to prepare U Canyon for demolition. The selected remedial action called first for consolidating and grouting equipment currently in the canyon into lower levels of the plant (openings called cells), after which the cell galleries, hot pipe trench, ventilation tunnel, drains and other voids below the operating deck and crane-way deck levels will be filled with approximately 20,000 cubic yards of grout and the canyon roof and walls demolished down to the approximate level of the canyon deck. The remaining canyon structure will then be buried beneath an engineered barrier designed to control potential contaminant migration for a 500-year life. Methods and lessons learned from this project will set the stage for the future demolition of Hanford's four other canyon-type processing facilities.

54 ENVIRONMENTAL SCIENCES↗

Thermal Performance of Uninsulated and Partially Filled Wall Cavities: Preprint

Low-rise, wood-framed homes are the most common type of residential structures in the United States. Wood wall construction supports roofs efficiently and provides a stable frame for attaching interior and exterior wall coverings. Wall cavities are prevalent and increase thermal resistance, particularly when they are filled with insulating material. This paper describes detailed computational fluid dynamics modeling to evaluate the thermal performance of uninsulated or partially filled wall cavities and accounts for conduction through framing, convection, and radiation. Parameters are ambient outdoor temperature, cavity surface emissivity, cavity aspect ratio, and insulation height. Understanding the thermal performance of uninsulated or partially insulated wall cavities is essential for conserving energy in residential buildings. The results can serve as input for building energy simulation tools such as DOE2 and EnergyPlus for modeling the temperature dependent energy performance of new and older homes with uninsulated or partially insulated walls.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Thermal Performance of Uninsulated and Partially Filled Wall Cavities

Wall cavities are widely present in the construction of low rise homes since wood framing is the most common type of construction for residential buildings in the United States. The primary function of such wall construction is to provide a stable frame to which interior and exterior wall coverings can be attached and by which a roof can be supported. The existence of wall cavities increases the thermal resistance of the enclosure, particularly when they are filled with insulating material. Several design guides provide data for prediction of the thermal resistance of uninsulated wall cavities of varying internal geometries. However, U-value coefficients provided in these guides do not account for partially insulated cavities or for variations in aspect ratio. Whole building energy simulation tools, like DOE2 or Energy Plus, use simplified, 1-D characterization of building envelopes. For the most part, this characterization assumes a fixed thermal resistance over the range of temperatures experienced by the enclosure. In reality, the thermal resistance is dominated by convection and radiation and is a function of several parameters, including the temperatures and emissivities of the cavity surfaces and the aspect ratio of the cavity. This study describes detailed CFD modeling to evaluate the thermal performance of uninsulated or partially filled wall cavities accounting for conduction through framing, convection, and radiation. The resulting correlations can serve as input for DOE2 and Energy Plus modeling of older homes, where the walls are either uninsulated or partially insulated due to the settling of the insulating material. Parameters of the study are the ambient temperature outdoors, emissivity of the cavity surfaces, cavity aspect ratio, and height of the insulation level. The outcomes of this study provide: An understanding of the thermal performance of uninsulated or partially insulated wall cavities, which is an essential aspect of energy conservation in residential buildings. Accurate input for whole building simulations models like DOE2 and Energy Plus in various climate zones. Recommendations on retrofit measures.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Field Study and Energy-Plus Benchmarks for Energy Saver Homes having Different Envelope Designs

An alliance to maximize energy efficiency and cost-effective residential construction (ZEBRAlliance) built and field tested four homes that are 50 percent more energy efficient than a code compliant home. The homes are unoccupied for the duration of a two-year field study, thereby eliminating the confounding issue of occupancy habits. All homes have about the same consistent and scheduled internal load. Each home showcases a unique envelope strategy: 1) structural insulated panel (SIP), 2) optimal value wall framing (OVF), 3) advanced framing featuring the benefits of insulations mixed with phase change materials (PCM), and 4) an exterior insulation and finish system (EIFS). All homes have different weather resistive barriers (WRBs) and/or air barriers to limit air and moisture infiltration. Three homes provide space conditioning and water heating via a ground loop heat exchanger, while the fourth home uses a high efficiency air-to-air heat pump and heat pump water heater. Field performance and results of EnergyPlus V7.0 benchmarks were made for roof and attics as compared to cathedral design and for wall heat flows to validate models. The moisture content of the wall sheathing is shown to prove the protecting effectiveness of WRBs. Temperature distributions through insulations in the wall and ceiling with and without PCMs are described to characterize the performance of the PCM building envelopes.

Attic↗

Building America Top Innovations 2012: Unvented, Conditioned Attics

This Building America Top Innovations profile describes Building America research showing an unvented attic insulated along the roof line provides better energy performance than a vented attic when HVAC ducts are located in the attic and there are numerous penetrations through the ceiling deck.

attic↗

Building America Case Study: Demonstration House of Cold-Climate Solutions for Affordable Housing, Minneapolis, Minnesota

Single family homes in urban areas that are available for renovation by nonprofit developers are often in rough shape (1MM to 2MM nationally). Budgeting has historically focused on improving homes to meet basic housing standards. A rising interest in the long-term impact of homeownership has introduced the need to balance basic needs with home performance. This demonstration project aims to help nonprofit affordable housing developers become familiar with three Building America performance measures, the installation processes, and impacts and benefits of each. A story and a half home in North Minneapolis, MN was presented by Urban Homeworks our local nonprofit partner. The team helped them install three researched upgrade measures: exterior roof insulation or 'overcoat,' exterior foundation insulation, or 'excavationless', and a combined space and water heating HVAC system or 'combi'. To maximize efficiency of application and to address budget issues, the Team worked with Urban Homeworks to identify ways to use volunteers and construction training programs to install the measures. An open invitation to visit the job site was extended to other nonprofit developers and industry partners to encourage dialog about the systems during live installation.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Efficient Solutions for Existing Homes Case Study: Demonstration House of Cold-Climate Solutions for Affordable Housing

Single family homes in urban areas that are available for renovation by nonprofit developers are often in rough shape (1MM to 2MM nationally). Budgeting has historically focused on improving homes to meet basic housing standards. A rising interest in the long-term impact of homeownership has introduced the need to balance basic needs with home performance. This demonstration project aims to help nonprofit affordable housing developers become familiar with three Building America performance measures, the installation processes, and impacts and benefits of each. A story and a half home in North Minneapolis, MN was presented by Urban Homeworks our local nonprofit partner. The team helped them install three researched upgrade measures: exterior roof insulation or 'overcoat,' exterior foundation insulation, or 'excavationless', and a combined space and water heating HVAC system or 'combi.'

affordable home renovation↗

Simplifying Energy Efficiency for Homeowners - Results from a California Utility's Pilot Study of a Scalable Solution to Assess Retrofit and Solar Opportunities: Preprint

For homeowners, typical choices to reduce net energy use in their homes include: upgrading their home with a tailored efficiency retrofit or investing in roof-top solar. Determining the unique combination of these options that will provide the most cost-effective solution requires analysis for each home. This analysis needs to be presented in a simple and actionable way to homeowners. The solution should also be easily scalable to thousands of homes to enable utilities to better target efficiency program options and support solar installations. Sacramento Municipal Utility District (SMUD) piloted a new tool developed by Vistar Energy called XeroHome that automates the assessment of energy efficiency and solar opportunities in existing homes. XeroHome demonstrates an approach to using building energy modeling, energy use data analytics and homeowner engagement to identify and target energy efficiency opportunities at scale. XeroHome uses automation to build an EnergyPlus model for each home, based on information from public data sources such as property assessment records, building permit records, aerial/satellite photography, and template models derived from ResStock. Utilizing cloud computing, machine learning and optimization algorithms, energy upgrade packages are ranked by cost-effectiveness for each home and presented over an interactive web-portal. This paper discusses SMUD's pilot project using XeroHome to conduct analysis for 1,500 existing homes in Sacramento, CA. Development of XeroHome's advanced analytics capabilities are discussed in the context of applicability for utility programs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Simplifying Energy Efficiency for Homeowners - Results from a California Utility's Pilot Study of a Scalable Solution to Assess Retrofit and Solar Opportunities

For homeowners, typical choices to reduce net energy use in their homes include: upgrading their home with a tailored efficiency retrofit or investing in roof-top solar. Determining the unique combination of these options that will provide the most cost-effective solution requires analysis for each home. This analysis needs to be presented in a simple and actionable way to homeowners. The solution should also be easily scalable to thousands of homes to enable utilities to better target efficiency program options and support solar installations. Sacramento Municipal Utility District (SMUD) piloted a new tool developed by Vistar Energy called XeroHome that automates the assessment of energy efficiency and solar opportunities in existing homes. XeroHome demonstrates an approach to using building energy modeling, energy use data analytics and homeowner engagement to identify and target energy efficiency opportunities at scale. XeroHome uses automation to build an EnergyPlus model for each home, based on information from public data sources such as property assessment records, building permit records, aerial/satellite photography, and template models derived from ResStock. Utilizing cloud computing, machine learning and optimization algorithms, energy upgrade packages are ranked by cost-effectiveness for each home and presented over an interactive web-portal. This paper discusses SMUD's pilot project using XeroHome to conduct analysis for 1,500 existing homes in Sacramento, CA. Development of XeroHome's advanced analytics capabilities are discussed in the context of applicability for utility programs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Analysis of Phenix end-of-life natural convection test with the MARS-LMR code

The end-of-life test of Phenix reactor performed by the CEA provided an opportunity to have reliable and valuable test data for the validation and verification of a SFR system analysis code. KAERI joined this international program for the analysis of Phenix end-of-life natural circulation test coordinated by the IAEA from 2008. The main objectives of this study were to evaluate the capability of existing SFR system analysis code MARS-LMR and to identify any limitation of the code. The analysis was performed in three stages: pre-test analysis, blind posttest analysis, and final post-test analysis. In the pre-test analysis, the design conditions provided by the CEA were used to obtain a prediction of the test. The blind post-test analysis was based on the test conditions measured during the tests but the test results were not provided from the CEA. The final post-test analysis was performed to predict the test results as accurate as possible by improving the previous modeling of the test. Based on the pre-test analysis and blind test analysis, the modeling for heat structures in the hot pool and cold pool, steel structures in the core, heat loss from roof and vessel, and the flow path at core outlet were reinforced in the final analysis. The results of the final post-test analysis could be characterized into three different phases. In the early phase, the MARS-LMR simulated the heat-up process correctly due to the enhanced heat structure modeling. In the mid phase before the opening of SG casing, the code reproduced the decrease of core outlet temperature successfully. Finally, in the later phase the increase of heat removal by the opening of the SG opening was well predicted with the MARS-LMR code. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Walmart Experimental Store Performance Stories: Preprint

Walmart opened two experimental stores--one in Colorado and one in Texas--in 2005 to serve as test beds for several advanced building systems. Each embodied more than 50 experiments covering materials, water systems, energy systems, and renewable energy production. Walmart worked for three years with the National Renewable Energy Laboratory for the Colorado Store and Oak Ridge National Laboratoryfor the Texas store to monitor, analyze, and report on their performance. HVAC experiments included waste oil boilers, a microturbine/absorption chiller combined heat and power system, evaporative cooling, and a transpired solar collector. The refrigeration systems integrated a medium-temperature secondary loop, evaporatively cooled condenser, doors on medium-temperature cases, andlight-emitting diodes on cases. Experiments in the lighting systems included a redesigned roof for clerestory daylighting and T-5 fluorescent lamps. Three photovoltaic systems for a total of 135 kW and a 50-kW wind turbine are also included. The energy system performance was compared to the measured performance of a prototypical Walmart store and to other benchmarks.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Thermal Management by Engineering the Alignment of Nanocellulose

One of the grand current research challenges is to improve the energy efficiency of residential and commercial buildings, which cumulatively consume more than 40% of the energy generated globally. In addition to improving the comfort of the inhabitants and mitigating the growing energy consumption problem, new building materials and technologies could provide a safe strategy for geoengineering to mitigate global climate change. Herein, recent progress in developing such advanced materials from nanocellulose, which is often derived from wood or even dirty feedstocks like waste, is reviewed. By using chemical and bacteria-enabled processing, nanocellulose can be used to fabricate broadband photonic reflectors, thermally super-insulating aerogels, solar gain regulators, and low-emissivity coatings, with potential applications in windows, roofs, walls, and other components of buildings envelopes. These material developments draw inspiration from advanced energy management found in nature, such as the nanoporous photonic structures that evolved in cuticles of beetles. Fabrication of such materials takes advantage of mesoscale liquid crystalline self-assembly, which allows for pre-designed control of cellulose nanoparticle orientations at the mesoscale. Finally, with the potential fully realized, such materials could one day transform the current energy-lossy buildings into energy plants on Earth and possibly even enable extraterrestrial habitats.

36 MATERIALS SCIENCE↗