Reduction of Beam Emittance of Pep-X Using Quadruple Bend Achromat Cell (open access)

Reduction of Beam Emittance of Pep-X Using Quadruple Bend Achromat Cell

SLAC National Accelerator Laboratory is studying an option of building a high brightness synchrotron light source machine, PEP-X, in the existing PEP-II tunnel [1, 2]. By replacing 6 arcs of FODO cells of PEPII High Energy Ring (HER) with two arcs of DBA and four arcs of TME and installation of 89.3 m long damping wiggler an ultra low beam emittance of 0.14 nm-rad (including intra-beam scattering) at 4.5 GeV is achieved. In this paper we study the possibility to further reduce the beam emittance by releasing the constraint of the dispersion free in the DBA straight. The QBA (Quadruple Bend Achromat) cell is used to replace the DBA. The ratio of outer and inner bending angle is optimized. The dispersion function in the non-dispersion straight is controlled to compromise with lower emittance and beam size at the dispersion straight. An undulator of period length 23 mm, maximum magnetic field of 1.053 T, and total periods of 150 is used to put in the 30 straights to simulate the effects of these IDs on the beam emittance and energy spread. The brightness including all the ID effects is calculated and compared to the original PEP-X design.
Date: May 26, 2009
Creator: Wang, Min-Huey; Cai, Yunhai; Hettel, Robert & Nosochkov, Yuri
Object Type: Article
System: The UNT Digital Library
Collins Mechanism Contributions to Single Spin Asymmetry (open access)

Collins Mechanism Contributions to Single Spin Asymmetry

We present recent developments on the single transverse spin physics, in particular, the Collins mechanism contributions in various hadronic reactions, such as semi-inclusive hadron production in DIS process, azimuthal distribution of hadron in high energy jet in pp collisions. We will demonstrate that the transverse momentum dependent and collinear factorization approaches are consistent with each other in the description of the Collins effects in the semi-inclusive hadron production in DIS process.
Date: May 26, 2009
Creator: Yuan,F.
Object Type: Article
System: The UNT Digital Library
Microbunching Instability in Velocity Bunching (open access)

Microbunching Instability in Velocity Bunching

Microbunching instability is one of the most challenging threats to FEL performances. The most effective ways to cure the microbunching instability include suppression of the density modulation sources and suppression of the amplification process. In this paper we study the microbunching instability in velocity bunching. Our simulations show that the initial current and energy modulations are suppressed in velocity bunching process, which may be attributed to the strong plasma oscillation and Landau damping from the relatively low beam energy and large relative slice energy spread. A heating effect that may be present in a long solenoid is also preliminarily analyzed.
Date: May 26, 2009
Creator: Xiang, D. & Wu, J.
Object Type: Article
System: The UNT Digital Library
Relationships between deformation and microstructure evolution and minimizing surface roughness after BCP processing in RRR Nb cavitites (open access)

Relationships between deformation and microstructure evolution and minimizing surface roughness after BCP processing in RRR Nb cavitites

Two strategies for improving the surface finish of niobium sheet used in superconducting radio frequency cavities were examined, using slices of single (or large-grain) material from an ingot, and equal channel angle extrusion (ECAE) preprocessing of ingot material to achieve a uniform and small grain size prior to subsequent rolling. The effect of these two processing paths on final microstructure, texture, and surface finish are discussed.
Date: May 26, 2009
Creator: Bieler, T. R.; Baars, D.; Hartwig, K. T.; Compton, C. & Grimm, T. L.
Object Type: Report
System: The UNT Digital Library
NAVIGATING A QUALITY ROUTE TO A NATIONAL SAFETY AWARD (open access)

NAVIGATING A QUALITY ROUTE TO A NATIONAL SAFETY AWARD

Deming quality methodologies applied to safety are recognized with the National Safety Council's annual Robert W. Campbell Award. Over the last ten years, the implementation of Statistical Process Control and quality methodologies at the U.S. Department of Energy's Hanford Site have contributed to improved safety. Improvements attributed to Statistical Process Control are evidenced in Occupational Safety and Health records and documented through several articles in Quality Progress and the American Society of Safety Engineers publication, Professional Safety. Statistical trending of safety, quality, and occurrence data continues to playa key role in improving safety and quality at what has been called the world's largest environmental cleanup project. DOE's Hanford Site played a pivotal role in the nation's defense beginning in the 1940s, when it was established as part of the Manhattan Project. After more than 50 years of producing material for nuclear weapons, Hanford, which covers 586 square miles in southeastern Washington state, is now focused on three outcomes: (1) Restoring the Columbia River corridor for multiple uses; (2) Transitioning the central plateau to support long-term waste management; and (3) Putting DOE assets to work for the future. The current environmental cleanup mission faces challenges of overlapping technical, political, regulatory, environmental, …
Date: May 26, 2009
Creator: SS, PREVETTE
Object Type: Article
System: The UNT Digital Library
Fracture toughness and crack-resistance curve behavior in metallic glass-matrix composites (open access)

Fracture toughness and crack-resistance curve behavior in metallic glass-matrix composites

Nonlinear-elastic fracture mechanics methods are used to assess the fracture toughness of bulk metallic glass (BMG) composites; results are compared with similar measurements for other monolithic and composite BMG alloys. Mechanistically, plastic shielding gives rise to characteristic resistance?curve behavior where the fracture resistance increases with crack extension. Specifically, confinement of damage by second?phase dendrites is shown to result in enhancement of the toughness by nearly an order of magnitude relative to unreinforced glass.
Date: May 26, 2009
Creator: Launey, Maximilien E.; Hofmann, Douglas C.; Suh, Jin-Yo; Kozachkov, Henry; Johnson, William L. & Ritchie, Robert O.
Object Type: Article
System: The UNT Digital Library
Undulator-Based Production of Polarized Positrons (open access)

Undulator-Based Production of Polarized Positrons

None
Date: May 26, 2009
Creator: Alexander, Gideon; Barley, John; Batygin, Yuri; Berridge, Steven; Bharadwaj, Vinod; Bower, Gary et al.
Object Type: Article
System: The UNT Digital Library
Start-to-End Simulations of the LCLS Accelerator and FEL Performance at Very Low Charge (open access)

Start-to-End Simulations of the LCLS Accelerator and FEL Performance at Very Low Charge

The Linac Coherent Light Source (LCLS) is an x-ray Free-electron Laser (FEL) being commissioned at Stanford Linear Accelerator Center (SLAC). Recent beam measurements have shown that, using the LCLS injector-linac-compressors, the beam emittance is very small at 20 pC. In this paper we perform start-to-end simulations of the entire accelerator including the FEL undulator and study the FEL performance versus the bunch charge. At 20 pC charge, these calculations associated with the measured beam parameters suggest the possibility of generating a longitudinally coherent single x-ray spike with 2-femtosecond (fs) duration at a wavelength of 1.5 nm. At 100 pC charge level, our simulations show an x-ray pulse with 10 femtosecond duration and up to 10{sup 12} photons at a wavelength of 1.5 {angstrom}. These results open exciting possibilities for ultrafast science and single shot molecular imaging.
Date: May 26, 2009
Creator: Ding, Y; Brachmann, A.; Decker, F. J.; Dowell, D.; Emma, P.; Frisch, J. et al.
Object Type: Article
System: The UNT Digital Library
Libby Mitigation Program, 2007 Annual Progress Report: Mitigation for the Construction and Operation of Libby Dam. (open access)

Libby Mitigation Program, 2007 Annual Progress Report: Mitigation for the Construction and Operation of Libby Dam.

Libby Reservoir was created under an International Columbia River Treaty between the United States and Canada for cooperative water development of the Columbia River Basin (Columbia River Treaty 1964). Libby Reservoir inundated 109 stream miles of the mainstem Kootenai River in the United States and Canada, and 40 miles of tributary streams in the U.S. that provided habitat for spawning, juvenile rearing, and migratory passage (Figure 1). The authorized purpose of the dam is to provide power (91.5%), flood control (8.3%), and navigation and other benefits (0.2%; Storm et al. 1982). The Pacific Northwest Power Act of 1980 recognized possible conflicts stemming from hydroelectric projects in the northwest and directed Bonneville Power Administration to 'protect, mitigate, and enhance fish and wildlife to the extent affected by the development and operation of any hydroelectric project of the Columbia River and its tributaries' (4(h)(10)(A)). Under the Act, the Northwest Power Planning Council was created and recommendations for a comprehensive fish and wildlife program were solicited from the region's federal, state, and tribal fish and wildlife agencies. Among Montana's recommendations was the proposal that research be initiated to quantify acceptable seasonal minimum pool elevations to maintain or enhance the existing fisheries (Graham et …
Date: May 26, 2009
Creator: Dunnigan, James; DeShazer, J. & Garrow, L.
Object Type: Report
System: The UNT Digital Library
Coherent Soft X-Ray Generation in the Water Window with the EEHG Scheme (open access)

Coherent Soft X-Ray Generation in the Water Window with the EEHG Scheme

Recently a scheme entitled echo-enabled harmonic generation (EEHG) was proposed for producing short wavelength FEL radiation that allows far higher harmonic numbers to be accessed as compared with the normal limit arising from incoherent energy spread. In this paper we study the feasibility of a single EEHG stage to generate coherent radiation in the 'water window' (2--4 nm wavelength) directly from a UV seed laser at 190-nm wavelength. We present time-dependent simulation results which demonstrate that the single-stage EEHG FEL can generate high power soft x-ray radiation in the water window with narrow bandwidth close to Fourier transform limit directly from a UV seed laser. The schemes to generate short x-ray pulse from femtosecond to attosecond using EEHG FEL are also discussed.
Date: May 26, 2009
Creator: Xiang, D. & Stupakov, G.
Object Type: Article
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

Installation of new Shortwave Spectrometer for permanent operation at SGP - In May 2006 the new ShortWave Spectrometer (SWS) was installed in the Optical Trailer at the Southern Great Plains Central Facility SGP on 27 April 2006. The SWS began full operation 28 April 2006 and has run continuously to the present. Over 25 GB of spectra has been collected, calibrated and archived. 3-D radiative transfer simulations - Retrieved fields of cloud optical thickness and effective radius to from the MODIS Airborne Simulator were used to reproduce 3D cloud fields that were used a input to 3D radiative transfer simulations and then compared with simultaneous Solar Spectral Flux Radiometer (SSFR) spectral irradiance measurements. The influence of both horizontal and vertical cloud structure, using accurate versus approximated optical properties in the radiative transfer model on the modeled irradiance was examined, as was the influence of using the full phase function versus using approximations of single scattering properties. In a related study, cloud microphysical and radiation data from two field experiments were compared measured irradiances with the modeled counterpart, using various 3D cloud models as input for two 3D radiative transfer models. Two papers were published. Direct measurement of aerosol radiative forcing …
Date: May 26, 2009
Creator: Pilewskie, Peter
Object Type: Report
System: The UNT Digital Library
D0 Solenoid Upgrade Project: Rectangular Liquid Helium Tube, Miscellaneous Information (open access)

D0 Solenoid Upgrade Project: Rectangular Liquid Helium Tube, Miscellaneous Information

This engineering note contains miscellaneous information about the rectangular liquid helium supply tube for the D-Zero solenoid. The information is fairly superficial, but could be used as a starting point for a future engineer who is going to specify and puchase the tubing. The chimney contains 4 conductors attached to an aluminum liquid helium supply tube. Because good thermal contact is desired, the tube will have flat sides. Aluminum is chosen to match the thermal contraction coefficient of the superconductor's aluminum stabilizer. The type of aluminum is chosen as 6061-T6 because it's allowable stress in ANSI/ASME B31.3 is higher than for other alloys. A different alloy could be chosen for extrusion reasons. The highest pressures this tubing should see will be during a quench. Current calculations predict the peak pressure during a quench to be 520 psi a for one-way relieving and 250 psia for two way relieving. Whatever the final alloy selection, the tubing needs to have a high enough allowable working pressure. There is very little room in the obround section of the chimney. In that portion the shape is rectangular, 12.7 mm (0.50-inch) x 31.8 mm (1.25-inch). A drawing shows the flow path cross section. This also …
Date: May 26, 1993
Creator: Rucinski, R.
Object Type: Report
System: The UNT Digital Library
UNREVIEWED DISPOSAL QUESTION EVALUATION: CENTER SLIT TRENCHES ONE THROUGH FIVE OPERATIONAL COVERS REANALYSIS (open access)

UNREVIEWED DISPOSAL QUESTION EVALUATION: CENTER SLIT TRENCHES ONE THROUGH FIVE OPERATIONAL COVERS REANALYSIS

Operational inventory limits for the disposal of solid low-level waste in Slit Trenches 1-7 were established by the Special Analysis (SA) performed by Collard and Hamm (2008). To determine disposal limits for the Slit Trenches, the SA followed the methodology used in the 2008 PA (WSRC, 2008) which assumed that the inventories in each trench were instantaneously placed in 12/1995, which is the date when SLIT1 began operation. The 2008 SA analyzed the impact from placing storm-water runoff covers simultaneously over Slit Trenches 1-7 at 5, 10 and 15 years after the inventory was introduced. To include a measure of conservatism in the limits, the lowest of the limits calculated for any storm-water runoff cover placement time or that calculated in the original 2008 PA was chosen as the operational limit for each radionuclide. Through the availability of funding provided by the American Recovery and Reinvestment Act (ARRA), storm-water runoff covers were placed over Slit Trenches 1-5 in December 2010. SRNL was requested to perform a UDQE for this accelerated action. Table 1 below lists the operational dates for Slit Trenches 1-5 and the time elapsed between when the first waste package was disposed in each Slit Trench and when …
Date: May 26, 2011
Creator: Smith, F. & Swingle, R.
Object Type: Report
System: The UNT Digital Library
QUALIFICATION OF THE SAVANNAH RIVER SITE 252CF SHUFFLER FOR RECEIPT VERIFICATION MEASUREMENTS OF MIXED U-PU OXIDES STORED IN 9975 SHIPPING CONTAINERS (open access)

QUALIFICATION OF THE SAVANNAH RIVER SITE 252CF SHUFFLER FOR RECEIPT VERIFICATION MEASUREMENTS OF MIXED U-PU OXIDES STORED IN 9975 SHIPPING CONTAINERS

To extend their ability to perform accountability and verification measurements of {sup 235}U in a U-Pu oxide matrix, the K-Area Material Storage facility commissioned the development and construction of a Passive/Active {sup 252}Cf Shuffler. A series of {sup 252}Cf, PuO{sub 2}, and U-Pu oxide standards, in addition to a single U{sub 3}O{sub 8} standard, were measured to characterize and calibrate the shuffler. Accompanying these measurements were simulations using MCNP5/MCNPX, aimed at isolating the neutron countrate contributions for each of the isotopes present. Two calibration methods for determining the {sup 235}U content in mixed UPu oxide were then developed, yielding comparable results. The first determines the {sup 235}U mass by estimating the {sup 239}Pu/{sup 235}U ratio-dependent contributions from the primary delayed neutron contributors. The second defines an average linear response based on the {sup 235}U and {sup 239}Pu mass contents. In each case, it was observed that self-shielding due to {sup 235}U mass has a large influence on the observed rates, requiring bounds on the applicable limits of each calibration method.
Date: May 26, 2011
Creator: Dubose, F.
Object Type: Article
System: The UNT Digital Library
Molecular Assemblies, Genes and Genomics Integrated Efficiently (MAGGIE) (open access)

Molecular Assemblies, Genes and Genomics Integrated Efficiently (MAGGIE)

Final report on MAGGIE. We set ambitious goals to model the functions of individual organisms and their community from molecular to systems scale. These scientific goals are driving the development of sophisticated algorithms to analyze large amounts of experimental measurements made using high throughput technologies to explain and predict how the environment influences biological function at multiple scales and how the microbial systems in turn modify the environment. By experimentally evaluating predictions made using these models we will test the degree to which our quantitative multiscale understanding wilt help to rationally steer individual microbes and their communities towards specific tasks. Towards this end we have made substantial progress towards understanding evolution of gene families, transcriptional structures, detailed structures of keystone molecular assemblies (proteins and complexes), protein interactions, biological networks, microbial interactions, and community structure. Using comparative analysis we have tracked the evolutionary history of gene functions to understand how novel functions evolve. One level up, we have used proteomics data, high-resolution genome tiling microarrays, and 5' RNA sequencing to revise genome annotations, discover new genes including ncRNAs, and map dynamically changing operon structures of five model organisms: For Desulfovibrio vulgaris Hildenborough, Pyrococcus furiosis, Sulfolobus solfataricus, Methanococcus maripaludis and Haiobacterium salinarum …
Date: May 26, 2011
Creator: Baliga, Nitin S.
Object Type: Report
System: The UNT Digital Library
Retardation of Uranium and Neptunium in Yucca Mountain Saturated Alluvium (open access)

Retardation of Uranium and Neptunium in Yucca Mountain Saturated Alluvium

None
Date: May 26, 2006
Creator: Sedlacek, C.; Schulmeister, M.; Reimus, P.; Scism, C.; Chipera, S. & Ding, M.
Object Type: Article
System: The UNT Digital Library
Secondary shock formation in xenon-nitrogen mixtures (open access)

Secondary shock formation in xenon-nitrogen mixtures

None
Date: May 26, 2006
Creator: Hansen, J. F.; Edwards, M. J.; Froula, D. H.; Edens, A. D.; Gregori, G. & Ditmire, T.
Object Type: Article
System: The UNT Digital Library
System Performance Characterization (open access)

System Performance Characterization

Characterizing an adaptive optics (AO) system refers to understanding its performance and limitations. The goal of an AO system is to correct wavefront aberrations. The uncorrected aberrations, called the residual errors and referred to in what follows simply as the errors, degrade the image quality in the science camera. Understanding the source of these errors is a great aid in designing an AO system and optimizing its performance. This chapter explains how to estimate the wavefront error terms and the relationship between the wavefront error and the degradation of the image. The analysis deals with the particular case of a HartmannShack wavefront sensor (WFS) and a continuous deformable mirror (DM), although the principles involved can be applied to any AO system.
Date: May 26, 2004
Creator: van Dam, M. A.
Object Type: Book
System: The UNT Digital Library
High concentration suspended sediment measurments using acontinuous fiber optic in-stream transmissometer (open access)

High concentration suspended sediment measurments using acontinuous fiber optic in-stream transmissometer

Suspended sediment loads mobilized during high flow periods in rivers and streams are largely uncharacterized. In smaller and intermittent streams, a large storm may transport a majority of the annual sediment budget. Therefore monitoring techniques that can measure high suspended sediment concentrations at semi-continuous time intervals are needed. A Fiber optic In-stream Transmissometer (FIT) is presented for continuous measurement of high concentration suspended sediment in storm runoff. FIT performance and precision were demonstrated to be reasonably good for suspended sediment concentrations up to 10g/L. The FIT was compared to two commercially available turbidity devices and provided better precision and accuracy at both high and low concentrations. Both turbidity devices were unable to collect measurements at concentrations greater than 4 g/L. The FIT and turbidity measurements were sensitive to sediment particle size. Particle size dependence of transmittance and turbidity measurement poses the greatest problem for calibration to suspended sediment concentration. While the FIT was demonstrated to provide acceptable measurements of high suspended sediment concentrations, approaches to real-time suspended sediment detection need to address the particle size dependence in concentration measurements.
Date: May 26, 2004
Creator: Campbell, Chris G.; Laycak, Danny T.; Hoppes, William; Tran,Nguyen T. & Shi, Frank G.
Object Type: Article
System: The UNT Digital Library
ESTIMATION OF THE WESTINGHOUSE 17X17 MOX SNF ASSEMBLY WEIGHT (open access)

ESTIMATION OF THE WESTINGHOUSE 17X17 MOX SNF ASSEMBLY WEIGHT

The purpose of this calculation is to obtain an estimate of a Westinghouse 17 x 17 mixed oxide (MOX) spent nuclear fuel (SNF) Vantage 5 assembly.
Date: May 26, 1998
Creator: McClure, J.
Object Type: Report
System: The UNT Digital Library
Special Analysis: Revision of Saltstone Vault 4 Disposal Limits (U) (open access)

Special Analysis: Revision of Saltstone Vault 4 Disposal Limits (U)

New disposal limits have been computed for Vault 4 of the Saltstone Disposal Facility based on several revisions to the models in the existing Performance Assessment and the Special Analysis issued in 2002. The most important changes are the use of a more rigorous groundwater flow and transport model, and consideration of radon emanation. Other revisions include refinement of the aquifer mesh to more accurately model the footprint of the vault, a new plutonium chemistry model accounting for the different transport properties of oxidation states III/IV and V/VI, use of variable infiltration rates to simulate degradation of the closure system, explicit calculation of gaseous releases and consideration of the effects of settlement and seismic activity on the vault structure. The disposal limits have been compared with the projected total inventory expected to be disposed in Vault 4. The resulting sum-of-fractions of the 1000-year disposal limits is 0.2, which indicates that the performance objectives and requirements of DOE 435.1 will not be exceeded. This SA has not altered the conceptual model (i.e., migration of radionuclides from the Saltstone waste form and Vault 4 to the environment via the processes of diffusion and advection) of the Saltstone PA (MMES 1992) nor has …
Date: May 26, 2005
Creator: Cook, J
Object Type: Report
System: The UNT Digital Library
Middle to Late Holocene Fluctuations of C3 and C4 Vegetation in a Northern New England Salt Marsh, Sprague Marsh, Phippsburg Maine (open access)

Middle to Late Holocene Fluctuations of C3 and C4 Vegetation in a Northern New England Salt Marsh, Sprague Marsh, Phippsburg Maine

A 3.1 meter sediment core was analyzed for stable carbon isotope composition of organic matter and higher plant leaf wax (HPLW) lipid biomarkers to determine Holocene shifts in C{sub 3} (higher high marsh) and C{sub 4} (low and/or high marsh) plant deposition at the Sprague River Salt Marsh, Phippsburg, Maine. The carbon isotope composition of the bulk sediment and the HPLW parallel each other throughout most of the core, suggesting that terrestrial plants are an important source of organic matter to the sediments, and diagenetic alteration of the bulk sediments is minimal. The current salt marsh began to form 2500 cal yr BP. Low and/or high C{sub 4} marsh plants dominated deposition at 2000 cal yr BP, 700 cal yr BP, and for the last 200 cal yr BP. Expansion of higher high marsh C{sub 3} plants occurred at 1300 and 600 cal yr BP. These major vegetation shifts result from a combination of changes in relative sea-level rise and sediment accumulation rates. Average annual carbon sequestration rates for the last 2500 years approximate 40 g C yr{sup -1} m{sup -2}, and are in strong agreement with other values published for the Gulf of Maine. Given that Maine salt marshes …
Date: May 26, 2006
Creator: Johnson, B J; Moore, K A; Lehmann, C; Bohlen, C & Brown, T A
Object Type: Article
System: The UNT Digital Library
Waste and Solvent Composition Limits for Modular Caustic-Side Solvent Extraction Unit (MCU) (open access)

Waste and Solvent Composition Limits for Modular Caustic-Side Solvent Extraction Unit (MCU)

This study examined waste feed and solvent limits for the Modular Caustic-Side Solvent Extraction Unit (MCU) currently being designed and built at the Savannah River Site (SRS) to remove cesium from highly alkaline radioactive waste. The study involved proposing ranges for 12 waste feed components (i.e., Na{sup +}, K{sup +}, Cs{sup +}, OH{sup -}, NO{sub 3}{sup -}, NO{sub 2}{sup -}, Cl{sup -}, F{sup -}, SO{sub 4}{sup 2-}, PO{sub 4}{sup 3-}, and CO{sub 3}{sup 2-}, and AlO{sub 2}{sup -}) through a compilation of SRS waste data. Statistical design methods were used to generate numerous wastes with varying compositions from the proposed ranges. An Oak Ridge National Laboratory (ORNL) model called SXFIT was used to predict the cesium extraction distribution coefficients (D-values) between the organic (solvent) phase and the aqueous waste phase using the waste component concentrations as inputs. The D-values from the SXFIT model were used as input along with MCU base case process parameters to a SASSE (Spreadsheet Algorithm for Stagewise Solvent Extraction) model to calculate final cesium concentrations for the MCU. The SASSE model was developed at Argonne National Laboratory (ANL). The SXFIT D-value and the waste component concentration data were used to develop a handier alternative model (neural …
Date: May 26, 2005
Creator: Adu-Wusu, Kofi; Waler, Douglas D. & Edwards, Thomas B
Object Type: Report
System: The UNT Digital Library
Electricity and Natural Gas Efficiency Improvements forResidential Gas Furnaces in the U.S. (open access)

Electricity and Natural Gas Efficiency Improvements forResidential Gas Furnaces in the U.S.

This paper presents analysis of the life-cycle costs for individual households and the aggregate energy and economic impacts from potential energy efficiency improvements in U.S. residential furnaces. Most homes in the US are heated by a central furnace attached to ducts for distributing heated air and fueled by natural gas. Electricity consumption by a furnace blower is significant, comparable to the annual electricity consumption of a major appliance. Since the same blower unit is also used during the summer to circulate cooled air in centrally air conditioned homes, electricity savings occur year round. Estimates are provided of the potential electricity savings from more efficient fans and motors. Current regulations require new residential gas-fired furnaces (not including mobile home furnaces) to meet or exceed 78 percent annual fuel utilization efficiency (AFUE), but in fact nearly all furnaces sold are at 80 percent AFUE or higher. The possibilities for higher fuel efficiency fall into two groups: more efficient non-condensing furnaces (81 percent AFUE) and condensing furnaces (90-96 percent AFUE). There are also options to increase the efficiency of the furnace blower. This paper reports the projected national energy and economic impacts of requiring higher efficiency furnaces in the future. Energy savings vary …
Date: May 26, 2006
Creator: Lekov, Alex; Franco, Victor; Meyers, Steve; McMahon, James E.; McNeil, Michael & Lutz, Jim
Object Type: Article
System: The UNT Digital Library