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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Advanced Envelope Research for Factory Built Housing, Phase 3 - Whole-House Prototyping

The Advanced Envelope Research effort will provide factory homebuilders with high performance, cost-effective envelope designs that can be effectively integrated into the plant production process while meeting the thermal requirements of the 2012 IECC standards. Given the affordable nature of manufactured homes, impact on first cost is a major consideration in developing new envelope technologies. This work is part of a multi-phase effort. Phase 1 identified seven envelope technologies and provided a preliminary assessment of three methods for building high performance walls. Phase 2 focused on developing viable product designs, manufacturing strategies, addressing code and structural issues, and cost analysis of the three selected options. An industry advisory committee helped narrow the research focus to perfecting a stud wall design with exterior continuous insulation (CI). Phase 3, completed in two stages, continued the design development effort, exploring and evaluating a range or methods for applying CI to factory built homes. The scope also included material selection, manufacturing and cost analysis, and prototyping and testing. During this phase, a home was built with CI, evaluated, and placed in service. The experience of building a mock up wall section with CI and then constructing on line a prototype home resolved important concerns about how to integrate the material into the production process. First steps were taken toward finding least expensive approaches for incorporating CI in standard factory building practices and a preliminary assessment suggested that even at this early stage the technology is attractive when viewed from a life cycle cost perspective.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2015

ORNL’s Envelope Stakeholder Workshop Proceedings

The 2015 Building Envelope Stakeholder Workshop hosted by Oak Ridge National Laboratory (ORNL) brought together representatives from diverse public and private entities. Presenters included senior Department of Energy (DOE) officials, ORNL personnel, and a myriad of corporate partners. To promote the use of energy-efficient technologies in commercial and residential buildings, the following issues were discussed: (1) Identifying current and anticipated barriers to the adoption of energy-efficient commercial envelope technologies; (2) Reviewing emerging and market-ready applications for new and existing commercial buildings; (3) Defining a path forward for commercial envelope products; and (5) Discussing and soliciting feedback on DOE’s strategic research road map for high-performance, moisture-managed envelope solutions for residential buildings This summary report describes key findings derived from these discussions as well as a distillation of the many discussions that unfolded during the event. It is hoped that it will be used not only to transmit this information to interested parties but also, more important, to foster continuing discussion and encourage input useful in furthering the broader goals of fostering the adoption of energy-efficient building technologies across various markets.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2012

Fort Benning Indianhead Townhome Renovations

The NAHB Research Center partnered with production builder Winchester/Camberley Homes to build a DOE Building America New Construction Test House (NCTH). This single family, detached house, located in the mixed-humid climate zone of Silver Spring, MD, was completed in June 2011. The primary goal for this house was to improve energy efficiency by 30% over the Building America B10 benchmark by developing and implementing an optimized energy solutions package design that could be cost effectively and reliably constructed on a production basis using quality management practices. The intent of this report is to outline the features of this house, discuss the implementation of the energy efficient design, and report on short-term testing results. During the interactive design process of this project, numerous iterations of the framing, air sealing, insulation, and space conditioning systems were evaluated for energy performance, cost, and practical implementation. The final design featured numerous advanced framing techniques, high levels of insulation, and the HVAC system entirely within conditioned space. Short-term testing confirmed a very tight thermal envelope and efficient and effective heating and cooling. In addition, relevant heating, cooling, humidity, energy, and wall cavity moisture data will be collected and presented in a future long-term report.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2012

Fort Benning Indianhead Townhome Renovations

The NAHB Research Center partnered with production builder Winchester/Camberley Homes to build a DOE Building America New Construction Test House (NCTH). This single family, detached house, located in the mixed-humid climate zone of Silver Spring, MD, was completed in June 2011. The primary goal for this house was to improve energy efficiency by 30% over the Building America B10 benchmark by developing and implementing an optimized energy solutions package design that could be cost effectively and reliably constructed on a production basis using quality management practices. The intent of this report is to outline the features of this house, discuss the implementation of the energy efficient design, and report on short-term testing results. During the interactive design process of this project, numerous iterations of the framing, air sealing, insulation, and space conditioning systems were evaluated for energy performance, cost, and practical implementation. The final design featured numerous advanced framing techniques, high levels of insulation, and the HVAC system entirely within conditioned space. Short-term testing confirmed a very tight thermal envelope and efficient and effective heating and cooling. In addition, relevant heating, cooling, humidity, energy, and wall cavity moisture data will be collected and presented in a future long-term report.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2026

Impact of Space Heating Options on Electricity Rates and Affordability

Electricity prices have increased in many regions of the U.S., with a national average of 18 cents/kWh projected for 2026, up from 16 cents/kWh in 2020. While the increases can be attributed to a number of factors, increasing electricity use in an efficient and strategic manner - with energy efficient building envelope upgrades and high performance HVAC systems - has the potential to increase revenue for utilities without significantly increasing electricity demand, and therefore could help moderate rate increases. This effect has been studied for electric vehicle charging[1] and dual-fuel heat pumps in Minnesota[2]. Leveraging a recently developed system cost methodology and FERC data on utility revenue, spending, and profits, this poster will present the direction and relative magnitude of rate impacts for efficient space heating upgrades in utility balancing areas across the contiguous U.S., using current prices and showing how the rate impacts would evolve under future grid scenarios.

15 GEOTHERMAL ENERGY↗
DOE OSTI2016

Design of a high efficiency relativistic backward wave oscillator with low guiding magnetic field

A high efficiency relativistic backward wave oscillator working at a low guiding magnetic field is designed and simulated. A trapezoidal resonant reflector is used to reduce the modulation field in the resonant reflector to avoid overmodulation of the electron beam which will lead to a large momentum spread and then low conversion efficiency. The envelope of the inner radius of the slow wave structure (SWS) increases stepwise to keep conformal to the trajectory of the electron beam which will alleviate the bombardment of the electron on the surface of the SWS. The length of period of the SWS is reduced gradually to make a better match between phase velocity and electron beam, which decelerates continually and improves the RF current distribution. Meanwhile the modulation field is reduced by the introduction of nonuniform SWS also. The particle in cell simulation results reveal that a microwave with a power of 1.8 GW and a frequency of 14.7 GHz is generated with an efficiency of 47% when the diode voltage is 620 kV, the beam current 6.1 kA, and the guiding magnetic field 0.95 T.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2021

Using non-invasive MEMS pressure sensors for measuring building envelope air leakage

Micro-electromechanical systems (MEMS)-based sensors have seen significant improvements in accuracy and cost over the past several years, and due to the need for altitude sensing in unmanned aerial vehicles and wearable technologies, absolute pressure sensors have shown the most dramatic improvements. This paper investigates applications of MEMS sensors in commercial buildings, including pairing two absolute pressure sensors to determine differential pressures between different locations in and around buildings. Differential pressure measurements are commonly made in commercial buildings for a number of applications, including static pressure measurements for variable-speed supply fan control, air balancing in hospitals, and for envelope and duct air leakage testing. This paper focuses specifically on envelope air-leakage testing applications of these sensors. The use of continuous pressure measurements in addition to one-time non-intrusive outdoor airflow measurements of rooftop packaged units is investigated. A comparison with standardized leakage testing indicated that continuous measurements with MEMS pressure-sensors were able to estimate envelope leakage to within 3–16% of the standardized test result. In addition, the magnitude and stability of differential pressure differences that can be resolved with absolute pressure sensors are also investigated in the laboratory and the field. Results show that the sensors can be effectively used for pressures seen in low rise buildings with rooftop units.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

Sustainable and Inexpensive Polydimethylsiloxane Sponges for Daytime Radiative Cooling

Radiative cooling is an emerging cooling technology that can passively release heat to the environment. To obtain a subambient cooling effect during the daytime, chemically engineered structural materials are widely explored to simultaneously reject sunlight and preserve strong thermal emission. However, many previously reported fabrication processes involve hazardous chemicals, which can hinder a material’s ability to be mass produced. In order to eliminate the hazardous chemicals used in the fabrication of previous works, this article reports a white polydimethylsiloxane (PDMS) sponge fabricated by a sustainable process using microsugar templates. By substituting the chemicals for sugar, the manufacturing procedure produces zero toxic waste and can also be endlessly recycled via methods widely used in the sugar industry. The obtained porous PDMS exhibits strong visible scattering and thermal emission, resulting in an efficient temperature reduction of 4.6 °C and cooling power of 43 W m –2 under direct solar irradiation. In addition, due to the air-filled voids within the PDMS sponge, its thermal conductivity remains low at 0.06 W (m K) –1 . This unique combination of radiative cooling and thermal insulation properties can efficiently suppress the heat exchange with the solar-heated rooftop or the environment, representing a promising future for new energy-efficient building envelope material.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

MODELING X-RAY BINARY EVOLUTION IN NORMAL GALAXIES: INSIGHTS FROM SINGS

We present the largest-scale comparison to date between observed extragalactic X-ray binary (XRB) populations and theoretical models of their production. We construct observational X-ray luminosity functions (oXLFs) using Chandra observations of 12 late-type galaxies from the Spitzer Infrared Nearby Galaxy Survey. For each galaxy, we obtain theoretical XLFs (tXLFs) by combining XRB synthetic models, constructed with the population synthesis code StarTrack, with observational star formation histories (SFHs). We identify highest-likelihood models both for individual galaxies and globally, averaged over the full galaxy sample. Individual tXLFs successfully reproduce about half of the oXLFs, but for some galaxies we are unable to find underlying source populations, indicating that galaxy SFHs and metallicities are not well matched and/or that XRB modeling requires calibration on larger observational samples. Given these limitations, we find that the best models are consistent with a product of common envelope ejection efficiency and central donor concentration {approx_equal} 0.1, and a 50% uniform-50% ''twins'' initial mass-ratio distribution. We present and discuss constituent subpopulations of tXLFs according to donor, accretor, and stellar population characteristics. The galaxy-wide X-ray luminosity due to low-mass and high-mass XRBs, estimated via our best global model tXLF, follows the general trend expected from the L{sub X} -star formation rate and L{sub X} -stellar mass relations of Lehmer et al. Our best models are also in agreement with modeling of the evolution of both XRBs over cosmic time and of the galaxy X-ray luminosity with redshift.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2014

THE BIRTH RATE OF SNe Ia FROM HYBRID CONe WHITE DWARFS

Considering the uncertainties of the C-burning rate (CBR) and the treatment of convective boundaries, Chen et al. found that there is a regime where it is possible to form hybrid CONe white dwarfs (WDs), i.e., ONe WDs with carbon-rich cores. As these hybrid WDs can be as massive as 1.30 M {sub ☉}, not much mass needs to be accreted for these objects to reach the Chandrasekhar limit and to explode as Type Ia supernovae (SNe Ia). We have investigated their contribution to the overall SN Ia birth rate and found that such SNe Ia tend to be relatively young with typical time delays between 0.1 and 1 Gyr, where some may be as young as 30 Myr. SNe Ia from hybrid CONe WDs may contribute several percent to all SNe Ia, depending on the common-envelope ejection efficiency and the CBR. We suggest that these SNe Ia may produce part of the 2002cx-like SN Ia class.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2012

Super Energy Efficiency Design (S.E.E.D.) Home Evaluation

This report describes the results of evaluation by the Alliance for Residential Building Innovation (ARBI) Building America team of the 'Super Energy Efficient Design' (S.E.E.D) home, a 1,935 sq. ft., single-story spec home located in Tucson, AZ. This prototype design was developed with the goal of providing an exceptionally energy efficient yet affordable home and includes numerous aggressiveenergy features intended to significantly reduce heating and cooling loads such as structural insulated panel (SIP) walls and roof, high performance windows, an ERV, an air-to-water heat pump with mixed-mode radiant and forced air delivery, solar water heating, and rooftop PV. Source energy savings are estimated at 45% over the Building America B10 Benchmark. System commissioning, short termtesting, long term monitoring and detailed analysis of results was conducted to identify the performance attributes and cost effectiveness of the whole house measure package.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2012

Super Energy Efficient Design (S.E.E.D.) Home Evaluation

This report describes the results of evaluation by the Alliance for Residential Building Innovation (ARBI) Building America team of the “Super Energy Efficient Design” (S.E.E.D) home, a 1,935 sq. ft., single-story spec home located in Tucson, AZ. This prototype design was developed with the goal of providing an exceptionally energy efficient yet affordable home and includes numerous aggressive energy features intended to significantly reduce heating and cooling loads such as structural insulated panel (SIP) walls and roof, high performance windows, an ERV, an air-to-water heat pump with mixed-mode radiant and forced air delivery, solar water heating, and rooftop PV. Source energy savings are estimated at 45% over the Building America B10 Benchmark. System commissioning, short term testing, long term monitoring and detailed analysis of results was conducted to identify the performance attributes and cost effectiveness of the whole house measure package.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

An Approach to High-Performance Affordable Housing Using Point-Source Space Conditioning

This project explored the use of minisplit ductless heat pumps in combination with small through-wall transfer fans to provide space conditioning in small single-story homes, including manufactured homes and homes built by Habitat for Humanity. The objectives were to reduce space-conditioning energy consumption by 50% compared to the 2009 International Energy Conservation Code (ICC 2009) while maintaining home affordability and thermal comfort. The strategy to achieve this goal also included a highly efficient thermal envelope to reduce space-conditioning loads.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

An Approach to High-Performance Affordable Housing Using Point-Source Space Conditioning

This project explored the use of minisplit ductless heat pumps in combination with small through-wall transfer fans to provide space conditioning in small single-story homes including manufactured homes and homes built by Habitat for Humanity. The objectives were to reduce space conditioning energy consumption by 50% compared to the 2009 International Energy Conservation Code while maintaining home affordability and thermal comfort. The strategy to achieve this goal also included a highly efficient thermal envelope to reduce space conditioning loads.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2016

Migration and growth of protoplanetary embryos. III. Mass and metallicity dependence for FGKM main-sequence stars

Radial velocity and transit surveys have found that the fraction of FGKM stars with close-in super-Earth(s) (η {sub ⊕}) is around 30%–50%, independent of the stellar mass M {sub *} and metallicity Z {sub *}. In contrast, the fraction of solar-type stars harboring one or more gas giants (η {sub J}) with masses M {sub p} > 100 M {sub ⊕} is nearly 10%–15%, and it appears to increase with both M {sub *} and Z {sub *}. Regardless of the properties of their host stars, the total mass of some multiple super-Earths systems exceeds the core mass of Jupiter and Saturn. We suggest that both super-Earths and supercritical cores of gas giants were assembled from a population of embryos that underwent convergent type I migration from their birthplaces to a transition location between viscously heated and irradiation-heated disk regions. We attribute the cause for the η {sub ⊕}–η {sub J} dichotomy to conditions required for embryos to merge and to acquire supercritical core mass (M{sub c}∼10 M{sub ⊕}) for the onset of efficient gaseous envelope accretion. We translate this condition into a critical disk accretion rate, and our analysis and simulation results show that it weakly depends on M {sub *} and decreases with metallicity of disk gas Z {sub d}. We find that embryos are more likely to merge into supercritical cores around relatively massive and metal-rich stars. This dependence accounts for the observed η {sub J}–M {sub *}. We also consider the Z{sub d}--Z{sub ∗} dispersed relationship and reproduce the observed η {sub J}–Z {sub *} correlation.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2021

An Approach to High-Performance Affordable Housing Using Point-Source Space Conditioning

In cooperation with the Building America Program, The Levy Partnership explored a variety of options to reduce space-conditioning energy consumption, working with partners to design, manu- facture, and build test homes in three states. The Levy Partnership tested the use of minisplit ductless heat pumps in combi- nation with small through-wall transfer fans to provide space conditioning in small single-story homes, including manufactured homes and homes built by Habitat for Humanity. The team set out to achieve 50% less energy consumption, compared to the 2009 International Energy Conservation Code, while maintaining home afford- ability and thermal comfort. The strategy also included a highly efficient thermal envelope to reduce space-conditioning loads.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2025

Enhancing EnergyPlus capabilities to model dynamic building envelopes using python plugin

Nearly half of the energy consumption in the United States is related to buildings, resulting in an urgent need to develop innovative technologies to improve building energy efficiency. Dynamic building envelopes, comprising switchable insulation and thermal energy storage materials, have been proposed recently as a promising solution to reduce buildings' heating and cooling loads by thermally coupling the indoor environment with the ambient environment when beneficial while decoupling them when outdoor conditions are not favorable. Although various related technologies are still underway, the whole-building energy modeling tools, like EnergyPlus, do not have the capability to simulate the transient and dynamic nature of dynamic envelope materials and components to accurately predict their impact on building energy use. The objective of this study is to formulate a method in EnergyPlus simulation engine to model multilayer envelopes, comprising dynamic building materials with variable thermophysical properties, and discuss the changes made to the program using a Python plugin. Furthermore, the thermal performance of the dynamic envelopes using the proposed method is compared and verified with the results from a well-established commercial code, COMSOL Multiphysics. A parametric assessment is also conducted to evaluate the energy efficiency benefits of dynamic envelopes in a single-family residential building, demonstrating total annual energy savings up to 11.6 %, when a dynamic envelope operates alone, and up to 18.2 % when it is combined with a thin layer of phase change material as a thermal storage medium. Finally, a United States wide energy efficiency assessment is presented to showcase the geographical spread of the energy savings. The method designed and implemented in this study provides the researchers with the ability to implement their dynamic insulation methods in EnergyPlus and evaluate the whole building energy impact.

25 ENERGY STORAGE↗
DOE OSTI2021

LCC-based framework for building envelope and structure co-design considering energy efficiency and natural hazard performance

Herein, this paper presents a life-cycle cost (LCC) informed co-design framework for building structures and envelope systems, holistically considering the influences of energy and natural hazard performance. The proposed method is consisted of a two-stage design and decision-making process, aiming to provide a quantitative guideline for building's structural and envelope co-design based on the its geographic locations. First, the building's structural configuration and envelope type are selected based on the life cycle cost. Then, the long-term cost effectiveness of various energy-saving building envelope options (e.g., high-performance glazing and insulation) is evaluated to refine the envelope design. The proposed co-design framework was demonstrated through the case study of a medium-size office building archetype in three locations with distinct climate conditions and seismic activities (i.e., Los Angeles, Memphis, and Boston). The results highlighted the interplay between building's structural (seismic) performance and the cost-effectiveness of energy-saving design options – e.g., for buildings located in high-seismic regions, seismic enhancing designs greatly reduce the paybak period of high performance building envelope by reducing the seismic loss; whereas for buildings located in regions with cold climate and low seismic risk such as Boston, spatial frame with high insulation building envelope shows the lowest LCC.

42 ENGINEERING↗