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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Test Report: Glovebox Test Fire for Evaluation of Effects on Containers and Windows

This test report describes a designed Glovebox (GB) fire to identify target environmental conditions that GB containers and windows are subject to such fires. The fire was designed by representatives from the Los Alamos National Laboratory (LANL) to replicate a realistic worst-case fire scenario at LANL. Key results of these experiments include: • The GB fire was active for more than 30 minutes. • Thermocouples were placed at multiple points in the GB were measured, including one on top of the container. Temperatures at varied widely as a function of location during the fires, as might be expected and as a function of proximity to fire, elevation in the GB, and in relation airflow present during the test, which constantly introduces room-temperature air into the GB. The maximum temperature recorded by a thermocouple was slightly less than 500°F at the elevation of the highest gloveports and near, but not in contact with the GB wall. • A thermographic camera imaged the region of the GB container during the fire. These data report container temperatures of up to approximately 900°F (482°C) over a period of several minutes. • Four kilograms of lead shot were held in the container. The majority of the shot melted during the course of the fire (lead melting point: 621°F/327°C). • Multiple windows fractured during the test. In some cases, the polymer interlayer of the laminated GB window glass appears to have sustained damage due to thermal breakdown of the polymer, though the interlayer of the laminated GB window glass appears to have remained intact in all cases. • The one window with an attached thermocouple was less affected by the fire. The attached thermocouple measured up to approximately 150°F. • Other thermocouples along (but not in contact with) the GB wall and closer to the fire (and cracked windows) reported up to approximately 200°C (392° F). These finding suggest that subjecting containers to 500°C for 45 minutes is bounding and representative for fires of this type. It should also be noted that 500°C (932°F) has been previously used as a test criterion for related work. Similarly, 200°C may be a reasonable target temperature for GB windows subjected to fires of this type.

42 ENGINEERING↗
DOE OSTI2025

Transforming Windows from Energy Liabilities to Zero-Energy Assets: Next-Generation Solutions for Buildings

Windows have traditionally contributed to a building's HVAC load, but they can also become a source of net energy gain or even operate as zero-energy components. For heating applications, highly insulating windows can harness more solar heat than the energy lost through them, transforming windows from energy liabilities to assets. Dynamic glazings provide further benefits by regulating solar heat gain, reducing cooling loads in summer and heating demands in winter. This simulation study focuses on developing the next generation of zero-energy windows (ZEW) for residential new construction. Through annual energy simulations across climate zones 1-8, ZEW performance benchmarks were established based on current code-level buildings, and we've identified the regions where meeting ZEW standards are most achievable. This work evaluates both static and dynamic window technologies, assessing their effects on annual energy use and cost. Key findings demonstrate that ZEW performance is achievable across diverse climate zones, with specific regional requirements. Most climate zones from 3-8 can achieve ZEW with specific configurations, while some warm climates (1-2) appear challenging for ZEW implementation. Climate zones 4-6 consistently allow for zero energy window implementation, offering multiple pathways through either static or dynamic window technologies. Colder climate zones (7-8) ZEW products allow for higher SHGC values while requiring low U-values.

Yu, Lili↗
DOE OSTI2018

Overview of Fabrication Techniques and Lessons Learned with Accelerator Vacuum Windows

Vacuum thin windows have been used in Fermilab's accelerators for decades and typically have been overlooked in terms of their criticality and fragility. Vacuum windows allow beam to pass through while creating a boundary between vacuum and air or high vacuum and low vacuum areas. The design of vacuum windows, including Titanium and Beryllium windows, will be discussed as well as fabrication, testing, and operational concerns. Failure of windows will be reviewed as well as safety approaches to mitigating failures and extending the lifetimes of vacuum windows. Various methods of calculating the strengths of vacuum windows will be explored, including FEA.

43 PARTICLE ACCELERATORS↗
DOE OSTI2018

Breaking the 20 Year Logjam to Better Insulating Windows

Windows account for about 4 Quads of US energy consumption or 12% of building energy use. After 20 years of public/private investment (from 1980 to 2000) in technology R&D, coupled with new rating and labeling organizations (NFRC) and with subsequent voluntary ENERGY STAR programs and tighter codes and standards, windows using low-E/argon gas fill (~R3) gained a dominant market share and now account for >86% of all annual sales. However, this remarkable transformation of prior markets has stagnated, with triple glazing (~R5-R7) comprising less than 2% of all window sales in 2016. U.S. Department of Energy (DOE) estimates the national technical potential savings using R5-R7 windows at ~ 2Q annually, but manufacturers claim they would have to redesign their entire sash/frame inventory to accommodate the thicker and heavier insulating glass units (IGUs) in conventional triple glazed window designs. This paper outlines the initial findings from the first phase of a new collaborative effort, now underway with industry partners, to transform window markets to the R5-R7 insulating levels by introducing a novel packaging of existing technology elements, implemented as a “drop-in replacement” for current IGUs. The program involves working with supply chain partners to ensure component availability, with leading window manufacturers to integrate the key technology elements and initially deploy the new designs, and with market pull partners to speed adoptions rates. Market pull partners include building code officials, utility rebate/incentive programs and ENERGY STAR, along with early adopters such as builders targeting net zero and passive house designers.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

Window Attachments: Possibilities for Utility Collaboration

Window attachments represent a new and exciting energy-efficient envelope measure for utilities. Collectively, windows in residential and commercial buildings are estimated to generate 32% of all HVAC heating and cooling loads. Very few programs offer incentives for installation of energy-efficient windows because the combined product and installation costs generally exceed the associated energy savings. However, preliminary data indicates that energy-efficient window attachments, including low-emissivity storm windows, cellular shades, and roller shades, can deliver cost-effective energy savings. DOE has committed more than $1.6 million to fund a new window attachment energy performance rating and certification organization – the Attachments Energy Rating Council – to enable consumers to make comparisons among window attachments. This paper is meant to help programs get up to speed on this new energy savings measure.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2023

Development of window scheduler algorithm exploiting natural ventilation and thermal mass for building energy simulation and smart home controls

Building energy simulations often rely on abstract assumptions when it comes to natural ventilation, such as ‘windows always open [or closed]’ or ‘windows open when outdoor temperature is below a certain threshold.’ However, simulations based on these assumptions fail to fully exploit the cooling potential of natural ventilation, as its effectiveness can be enhanced or diminished by various factors, including the presence of thermal mass. This issue also extends to smart home controls, where determining the window schedule becomes challenging without information about the building's response to outdoor conditions. To address these issues, this study has developed an analytical model for window operation schedules that leverages the passive cooling from natural ventilation. The analytical model was validated against a Modelica simulation. A case study utilizing the BESTEST model of ANSI/ASHRAE Standard 140 underwent validation with EnergyPlus simulations, showing strong concordance. The algorithm provides window schedule recommendations adapted to various airflow rates, thermal masses, and climate variations. Notably, the case study demonstrated that proper window scheduling could reduce indoor temperature by up to 8 °C under the given simulation settings, thereby improving resilience and indicating potential energy savings. Furthermore, the paper explores the potential opportunities and challenges this approach presents, especially for building simulation and smart home applications.

42 ENGINEERING↗
DOE OSTI2013

Characterization of Energy Savings and Thermal Comfort Improvements Derived from Using Interior Storm Windows

This field study of a single historic home in Seattle, WA documents the performance of Indow ® Windows’s interior storm window inserts. Energy use and the temperature profile of the house were monitored before and after the installation of the window inserts and changes in the two recorded metrics were examined. Using the defined analysis approach, it was determined that the interior storm windows produced a 22% reduction of the HVAC energy bill and had an undetermined effect on the thermal comfort in the house. Although there was no measurable changes in the thermal comfort of the house, the occupant noted the house to be “warmer in the winter and cooler in the summer” and that the “temperatures are more even (throughout the house).” The interior storm windows were found to be not cost effective, largely due to the retrofits completed on its heating system. However, if the economic analysis was conducted based on the old heating system, a 72% efficient oil fired furnace, the Indow Windows proved to be economical and had a simple payback period of 9.0 years.

high performance housing↗
DOE OSTI2013

Highly Insulating Windows Volume Purchase Program (Final Report)

This report documents the development, execution outcomes and lessons learned of the Highly Insulating Windows Volume Purchase (WVP) Program carried out over a three-year period from 2009 through 2012. The primary goals of the program were met: 1) reduce the incremental cost of highly insulating windows compared to ENERGY STAR windows; and 2) raise the public and potential buyers’ awareness of highly insulating windows and their benefits. A key outcome of the program is that the 2013 ENERGY STAR Most Efficient criteria for primary residential windows were adopted from the technical specifications set forth in the WVP program.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2022

Pathway to Zero Energy Windows: Advancing Technologies and Market Adoption

Improving the performance of windows has the potential to reduce U.S. annual energy use by 1.7% and CO2 emissions by 1.9% in 2050. Beyond static windows, dynamic technologies could reduce U.S. annual energy use by 1.6 quads and CO2 emissions by 68 million metric tons. In addition, the widespread adoption of static and dynamic technologies would substantially reduce peak electricity demand from buildings. Beyond energy use and CO2 emissions reductions, improving window performance will increase occupant comfort and well-being. In a new report, Pathway to Zero Energy Windows: Advancing Technologies and Market Adoption, the U.S. Department of Energy (DOE) outlines multiple avenues for technology development, deployment, and adoption to increase the impact that windows can have on decarbonizing America's buildings.

building energy efficiency↗
DOE OSTI2016

Waveguide transition with vacuum window for multiband dynamic nuclear polarization systems

A low loss waveguide transition section and oversized microwave vacuum window covering several frequency bands (94 GHz, 140 GHz, 188 GHz) is presented. The transition is compact and was optimized for multiband Dynamic Nuclear Polarization (DNP) systems in a full-wave simulator. The window is more broadband than commercially available windows, which are usually optimized for single band operation. It is demonstrated that high-density polyethylene with urethane adhesive can be used as a low loss microwave vacuum window in multiband DNP systems. The overall assembly performance and dimensions are found using full-wave simulations. The practical aspects of the window implementation in the waveguide are discussed. To verify the design and simulation results, the window is tested experimentally at the three frequencies of interest.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2013

High Performance Window Retrofit

The US Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) and Traco partnered to develop high-performance windows for commercial building that are cost-effective. The main performance requirement for these windows was that they needed to have an R-value of at least 5 ft 2 ∙ F∙h/Btu. This project seeks to quantify the potential energy savings from installing these windows in commercial buildings that are at least 20 years old. To this end, we are conducting evaluations at a two-story test facility that is representative of a commercial building from the 1980s, and are gathering measurements on the performance of its windows before and after double-pane, clear-glazed units are upgraded with R5 windows. Additionally, we will use these data to calibrate EnergyPlus models that we will allow us to extrapolate results to other climates. Findings from this project will provide empirical data on the benefits from high-performance windows, which will help promote their adoption in new and existing commercial buildings. This report describes the experimental setup, and includes some of the field and simulation results.

EnergyPlus↗
DOE OSTI2017

Window to the Hot Cell: The Challenges of Repairing a Specialized Nuclear Containment

Here, at the Idaho National Laboratory (INL) nuclear R&D site we come across a myriad of challenges and health hazards. Recently, a first time activity for the INL was to replace a hot cell window put in place circa 1977. This job evolution was complex in nature and involved several health and safety hazards. A hot cell is a containment designed to protect workers from radioactivity yet continue to allow work with remote handled tools and windows for visibility. The hot cell window weighed approximately 14,000 lbs. and was held in place by 1.6 cubic yards of high density grout. Removal of the window required abrasive grout removal techniques, radiological control efforts, specialized ventilation, and personal protective equipment utilization. In order to contain the large amounts of dust from the removal of concrete and potential contamination exposure a special containment tent and ventilation system was designed to protect workers in the surrounding areas from dust and debris. Once the window was removed it had to be further taken apart for shipment. While performing this activity, several lead sheets and lead wool was required to be removed. Overall it took 38 days to accomplish this task and had several organizations involved. There were no injuries or unexpected conditions that occurred during this job task. This was the first time this activity was performed at the INL and was completed in a successful manner. Further windows are set to be replaced in the near future.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2018

The F-t-Pj-RG method: An adjacent-rolling-windows based steady-state detection technique for application to kinetic Monte Carlo simulations

A window-based steady-state detection algorithm has been developed for application to kinetic Monte Carlo simulation data. The algorithm, termed F-t-Pj-RG sequentially applies an F-test, a t-test, and a projection test on adjacent windows of the data while rolling (or shifting) and growing the windows when any of the tests fail. In aggregate, the algorithm is able to (a) automatically reject the warm-up period as not being at steady-state, as well as (b) determine an appropriate window size for converged statistics when sampling the data, which is necessary for detection of steady-state, and (c) detect steady-state within a particular tolerance. The last step, the projection test, is actually an oscillating-slope projection test, and is performed on j sequential data windows (i.e., more than two adjacent windows). It requires more than simply being within the user defined tolerance: the oscillating-slope projection test includes a condition that the slope must oscillate around zero when 2, which is an additional indication of steady-state. When all three tests are passed, the F-t-Pj test is passed, indicating that the prerequisites of steady-state detection have been met and also that conditions consistent with the definition of steady-state have been realized. This algorithm is applied to a variety of data sets that correspond to the diverse type of data trends that can be produced by kinetic Monte Carlo simulations. The algorithm is shown to be robust in its ability to handle differing functional forms, and is able to detect steady-state with low computational cost. Finally, the low computational cost of this method and its robustness towards varied data trends make it suitable for on-the-fly use in kinetic Monte Carlo simulations.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2025

Si–Cl 2 –Ar + Atomic Layer Etching Window: A Fundamental Study Using Molecular Dynamics Simulations and a Reduced Order Model

Silicon (Si) atomic layer etching (ALE) by alternating exposure to chlorine gas (Cl 2 ) and argon ions (Ar + ) is studied by using molecular dynamics (MD) simulations and a reduced order model (ROM). Here, the purpose of this study is to elucidate the properties of the ALE window, a range of ion energies where the amount of Si etched over a series of cycles is nonzero and nearly independent of ion energy. Experimental studies of the Si–Cl 2 –Ar + ALE system report contradictory results related to the ALE window’s ion energy range. Both MD simulations and the ROM show that there is an ALE window present from approximately 15 to 20 eV for normal incidence argon ions. The Si–Cl 2 –Ar + system, therefore, exhibits a narrow ALE window. The amount of Si etched per cycle is less than one atomic layer because of the higher etch yield of Cl atoms relative to atomic Si and silicon chlorides. A modified version of the ROM with an artificially increased Si physical sputtering threshold energy expands the ALE window, illustrating the importance of the difference in chemical and physical sputtering threshold energies in the ALE window energy range. The ROM is also used to examine the dependence of the EPC on the Ar + ion fluence.

energy↗
DOE OSTI2019

Hybrid dynamic windows using reversible metal electrodeposition and ion insertion

Dynamic windows with electronically controlled transmission reduce glare without obstructing views while increasing the energy efficiency of buildings and automobiles via lighting, heating and cooling savings. Electrochromic materials, which change colour with voltage, are widely explored for use in dynamic windows, but they have not been extensively commercialized due to problems associated with colour, cost, switching speed and durability. Here, we develop a class of dynamic windows that combines reversible metal electrodeposition with ion insertion chemistry. These devices function through the reversible electroplating of Bi and Cu at the working electrode and Li+ insertion in a nickel oxide counter electrode. In one minute, 100 cm 2 windows uniformly switch between a clear state with 75% transmission and a colour-neutral black state possessing 10% transmission, which represents a significant improvement over previous metal-based architectures. We demonstrate that these hybrid windows cycle at least 4,000 times without degradation and are compatible with flexible substrates. Finally, we discuss how this approach can be used to design practical large-scale windows.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Polymer Inhibitors Enable >900 cm2 Dynamic Windows Based on Reversible Metal Electrodeposition with High Solar Modulation

Dynamic windows with adjustable tint give users control over the flow of light and heat to decrease the carbon footprint of buildings and improve the occupants’ comfort. Despite the benefits of dynamic windows, they are rarely deployed in buildings because the existing technology cannot achieve fast and colour-neutral tinting at an agreeable cost. Reversible metal electrodeposition is a promising approach to solve these problems. Here, we demonstrate the use of polymer inhibitors to reversibly deposit metal films with controlled morphology in dynamic windows. The windows that employ the polymer inhibitor can readily tint to below 0.001% visible transmittance in less than 3 min and exhibit high infrared reflectance (>70%), colour-neutral transmittance (C*<5) and an ultrawide range of optical and solar modulation (..delta..Tvis=0.76 and ..delta..SHGC=0.56). The polymer inhibitors also increase the efficiency and improve the durability of the windows and enable construction of >900 cm2 dynamic windows with fast response and excellent uniformity.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Identification of a window for quiescent H-mode operation in MHD stability diagram of DIII-D plasmas

A window for quiescent H-mode (QH-mode) operation in DIII-D plasmas in the diagram of pedestal magnetohydrodynamic (MHD) stability was identified through linear MHD stability analysis, accounting for the effects of plasma rotation and ion diamagnetic drift. The operation window lies between the stability boundaries of the kink/peeling mode (K/PM) identified with and without the inclusion of plasma rotation effects. In this region, the mode remains unstable unless rotation effects are considered alongside the ion diamagnetic drift, which is consistently included in the analysis. The stabilization of the MHD mode, facilitated by the coupled effects of plasma rotation and ion diamagnetic drift, plays a crucial role in widening the window, enabling the attainment of the QH-mode state. Furthermore, the suppression of edge localized modes (ELM) can be achieved by controlling the pedestal structure to ensure the plasma state remains within the operation window. The location of the operation window in the stability diagram depends on the K/PM stability properties. Therefore, optimizing conditions for QH-mode requires adjustments based on changes in stability characteristics. A pressure pedestal and its associated bootstrap current density near the last closed flux surface are advantageous for situating the plasma state within the window. However, excessive current density can trigger ELMs. This trend was confirmed through comparisons of MHD stability diagrams between QH-mode and ELMy H-mode plasmas.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2023

On the impact of the galaxy window function on cosmological parameter estimation

One important source of systematics in galaxy redshift surveys comes from the estimation of the galaxy window function. Up until now, the impact of the uncertainty in estimating the galaxy window function on parameter inference has not been properly studied. In this paper, we show that the uncertainty and the bias in estimating the galaxy window function will be salient for ongoing and next-generation galaxy surveys using a simulation-based approach. With a specific case study of cross-correlating emission-line galaxies from the DESI Legacy Imaging Surveys and the Planck cosmic microwave background lensing map, we show that neural network-based regression approaches to modelling the window function are superior in comparison to linear regression-based models. Here, we additionally show that the definition of the galaxy overdensity estimator can impact the overall signal-to-noise of observed power spectra. Finally, we show that the additive biases coming from the window functions can significantly bias the modes of the inferred parameters and also degrade their precision. Thus, a careful understanding of the window functions will be essential to conduct cosmological experiments.

79 ASTRONOMY AND ASTROPHYSICS↗