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Lifecycle Assessment of Beijing-Area Building Energy Use and Emissions: Summary Findings and Policy Applications

Description: Buildings are at the locus of three trends driving China's increased energy use and emissions: urbanization, growing personal consumption, and surging heavy industrial production. Migration to cities and urban growth create demand for new building construction. Higher levels of per-capita income and consumption drive building operational energy use with demand for higher intensity lighting, thermal comfort, and plug-load power. Demand for new buildings, infrastructure, and electricity requires heavy industrial production. In order to quantify the implications of China's ongoing urbanization, rising personal consumption, and booming heavy industrial sector, this study presents a lifecycle assessment (LCA) of the energy use and carbon emissions related to residential and commercial buildings. The purpose of the LCA model is to quantify the impact of a given building and identify policy linkages to mitigate energy demand and emissions growth related to China's new building construction. As efficiency has become a higher priority with growing energy demand, policy and academic attention to buildings has focused primarily on operational energy use. Existing studies estimate that building operational energy consumption accounts for approximately 25% of total primary energy use in China. However, buildings also require energy for mining, extracting, processing, manufacturing, and transporting materials, as well as energy for construction, maintenance, and decommissioning. Building and supporting infrastructure construction is a major driver of industry consumption--in 2008 industry accounted for 72% of total Chinese energy use. The magnitude of new building construction is large in China--in 2007, for example, total built floor area reached 58 billion square meters. During the construction boom in 2007 and 2008, more than two billion m{sup 2} of building space were added annually; China's recent construction is estimated to account for half of global construction. Lawrence Berkeley National Laboratory (LBNL) developed an integrated LCA model to capture the energy and emissions implications of all ...
Date: September 15, 2010
Creator: Aden, Nathaniel; Qin, Yining & Fridley, David
Partner: UNT Libraries Government Documents Department

INFRARED and PHOTOELECTRON SPECTROSCOPIC STUDY OF S02 OXIDATION ON SOOT PARTICLES

Description: Results obtained by means of x-ray photoelectron spectroscopy and internal reflection infrared spectroscopy demonstrate the feasibility of heterogeneous oxidation of sulfur dioxide on soot particles in air. Sulfuric acid formed in this process can be neutralized on basic surface sites of soot particles, resulting in the formation of carbonium and/or oxonium sulfate. Hydrolysis of these salts into cyclic hemiacetals and sulfuric acid is expected.
Date: December 1, 1975
Creator: Chang, S.G. & Novakov, T.
Partner: UNT Libraries Government Documents Department

SOOT-CATALYZED OXIDATION OF SULFUR DIOXIDE

Description: Experimental results are reviewed which demonstrate that combustion-generated soot particles can oxidize SO{sub 2} in both the absence ('dry' mechanism) and the presence ('wet' mechanism) of liquid water. The 'wet' mechanism is much more efficient than the 'dry' one, and is applicable to situations where the aerosol particles are covered with a liquid water layer. Calculations are presented which suggest that the soot-catalyzed oxidation of SO{sub 2} can be the dominant mechanism under realistic atmospheric conditions.
Date: May 1, 1978
Creator: Chang, S.G. & Novakov, T.
Partner: UNT Libraries Government Documents Department

Measuring solar reflectance Part I: Defining a metric that accurately predicts solar heat gain

Description: Solar reflectance can vary with the spectral and angular distributions of incident sunlight, which in turn depend on surface orientation, solar position and atmospheric conditions. A widely used solar reflectance metric based on the ASTM Standard E891 beam-normal solar spectral irradiance underestimates the solar heat gain of a spectrally selective 'cool colored' surface because this irradiance contains a greater fraction of near-infrared light than typically found in ordinary (unconcentrated) global sunlight. At mainland U.S. latitudes, this metric RE891BN can underestimate the annual peak solar heat gain of a typical roof or pavement (slope {le} 5:12 [23{sup o}]) by as much as 89 W m{sup -2}, and underestimate its peak surface temperature by up to 5 K. Using R{sub E891BN} to characterize roofs in a building energy simulation can exaggerate the economic value N of annual cool-roof net energy savings by as much as 23%. We define clear-sky air mass one global horizontal ('AM1GH') solar reflectance R{sub g,0}, a simple and easily measured property that more accurately predicts solar heat gain. R{sub g,0} predicts the annual peak solar heat gain of a roof or pavement to within 2 W m{sup -2}, and overestimates N by no more than 3%. R{sub g,0} is well suited to rating the solar reflectances of roofs, pavements and walls. We show in Part II that R{sub g,0} can be easily and accurately measured with a pyranometer, a solar spectrophotometer or version 6 of the Solar Spectrum Reflectometer.
Date: May 14, 2010
Creator: Levinson, Ronnen; Akbari, Hashem & Berdahl, Paul
Partner: UNT Libraries Government Documents Department

Measuring solar reflectance Part II: Review of practical methods

Description: A companion article explored how solar reflectance varies with surface orientation and solar position, and found that clear sky air mass 1 global horizontal (AM1GH) solar reflectance is a preferred quantity for estimating solar heat gain. In this study we show that AM1GH solar reflectance R{sub g,0} can be accurately measured with a pyranometer, a solar spectrophotometer, or an updated edition of the Solar Spectrum Reflectometer (version 6). Of primary concern are errors that result from variations in the spectral and angular distributions of incident sunlight. Neglecting shadow, background and instrument errors, the conventional pyranometer technique can measure R{sub g,0} to within 0.01 for surface slopes up to 5:12 [23{sup o}], and to within 0.02 for surface slopes up to 12:12 [45{sup o}]. An alternative pyranometer method minimizes shadow errors and can be used to measure R{sub g,0} of a surface as small as 1 m in diameter. The accuracy with which it can measure R{sub g,0} is otherwise comparable to that of the conventional pyranometer technique. A solar spectrophotometer can be used to determine R*{sub g,0}, a solar reflectance computed by averaging solar spectral reflectance weighted with AM1GH solar spectral irradiance. Neglecting instrument errors, R*{sub g,0} matches R{sub g,0} to within 0.006. The air mass 1.5 solar reflectance measured with version 5 of the Solar Spectrum Reflectometer can differ from R*{sub g,0} by as much as 0.08, but the AM1GH output of version 6 of this instrument matches R*{sub g,0} to within about 0.01.
Date: May 14, 2010
Creator: Levinson, Ronnen; Akbari, Hashem & Berdahl, Paul
Partner: UNT Libraries Government Documents Department

Use Patterns of LED Flashlights in Kenya and a One-Year Cost Analysis of Flashlight Ownership

Description: Flashlight usage is widespread across much of sub-Saharan Africa.1 In Kenya in particular, over half of all households report owning a flashlight (Kamfor, 2002). Aside from household use, flashlights are also widely used to perform income-earning jobs in Kenya. Lumina Research Note No.4, the first report in this series documenting flashlight use in Kenya, highlights flashlight use patterns of night watchmen and bicycle taxi drivers. Both of these are occupations that rely on the use of flashlights on a nightly basis (Tracy et al., 2009). Also highlighted by Research Note No.4, flashlight users in Kenya have reported being highly dissatisfied with the quality of the low-cost LED flashlights that are available, and they identify several reoccurring problems they have faced as flashlight end-users (Tracy et al., 2009). The fact that there exists a substantial dependency upon flashlights in Kenya and that users are disgruntled with the available products suggests reasons for concern about flashlight quality. This concern is present despite two recent technological transitions in the flashlight market. First, LED technology has quickly emerged as the dominant source of portable lighting in Kenya, outpacing incandescent flashlights (Johnstone et al., 2009). LED technology has the potential to provide efficiency and performance benefits relative to incandescent bulbs, and low-cost LEDs have achieved price levels that make them cost competitive with conventional lighting sources for a number of applications (Mills, 2005). Second, rechargeable sealed-lead acid (SLA) batteries are also becoming more prevalent alternatives to disposable dry cell batteries. Flashlights using rechargeable SLA batteries tend to have a lower total cost of ownership over a two-year period than a flashlight using dry cell batteries (Radecsky, 2009); however, as this current report highlights, this may vary depending on the intensity of use patterns. To avoid a potential market spoiling effect for off-grid lighting products based ...
Date: February 16, 2010
Creator: Tracy, Jennifer; Jacobson, Arne & Mills, Evan
Partner: UNT Libraries Government Documents Department

Value and Technology Assessment to Enhance the Business Case for the CERTS Microgrid

Description: The CERTS Microgrid concept is an advanced approach for enabling integration of, in principle, an unlimited quantity of distributed energy resources into the electricity grid. A key feature of a microgrid, is its ability, during a utility grid disturbance, to separate and isolate itself from the utility seamlessly with no disruption to the loads within the microgrid (including no reduction in power quality). Then, when the utility grid returns to normal, the microgrid automatically resynchronizes and reconnects itself to the grid, in an equally seamless fashion. What is unique about the CERTS Microgrid is that it can provide this technically challenging functionality without extensive (i.e., expensive) custom engineering. In addition, the design of the CERTS Microgrid also provides high system reliability and great flexibility in the placement of distributed generation within the microgrid. The CERTS Microgrid offers these functionalities at much lower costs than traditional approaches by incorporating peer-to-peer and plug-and-play concepts for each component within the Microgrid. The predecessor to the current project involved the construction of and completion of initial testing using the world's first, full-scale, inverter-based, distributed generation test bed. The project demonstrated three advanced techniques, collectively referred to as the CERTS Microgrid concept, which collectively significantly reduce the level of custom field engineering needed to operate microgrids consisting of small generating sources. The techniques are: (1) a method for effecting automatic and seamless transitions between grid-connected and islanded modes of operation; (2) an approach to electrical protection within the microgrid that does not depend on high fault currents; and (3) a method for microgrid control that achieves voltage and frequency stability under both grid and islanded conditions without requiring high-speed communications. The work conducted in this phase of RD&D on the CERTS Microgrid Concept builds upon this base of technical accomplishments to prioritize, develop, and then ...
Date: May 15, 2010
Creator: Lasseter, Robert & Eto, Joe
Partner: UNT Libraries Government Documents Department

Wind Power: How Much, How Soon, and At What Cost?

Description: The global wind power market has been growing at a phenomenal pace, driven by favorable policies towards renewable energy and the improving economics of wind projects. On a going forward basis, utility-scale wind power offers the potential for significant reductions in the carbon footprint of the electricity sector. Specifically, the global wind resource is vast and, though accessing this potential is not costless or lacking in barriers, wind power can be developed at scale in the near to medium term at what promises to be an acceptable cost.
Date: January 1, 2010
Creator: Wiser, Ryan H & Hand, Maureen
Partner: UNT Libraries Government Documents Department

A Pilot Study of the Effectiveness of Indoor Plants for Removal of Volatile Organic Compounds in Indoor Air in a Seven-Story Office Building

Description: The Paharpur Business Centre and Software Technology Incubator Park (PBC) is a 7 story, 50,400 ft{sup 2} office building located near Nehru Place in New Delhi India. The occupancy of the building at full normal operations is about 500 people. The building management philosophy embodies innovation in energy efficiency while providing full service and a comfortable, safe, healthy environment to the occupants. Provision of excellent Indoor Air Quality (IAQ) is an expressed goal of the facility, and the management has gone to great lengths to achieve it. This is particularly challenging in New Delhi, where ambient urban pollution levels rank among the worst on the planet. The approach to provide good IAQ in the building includes a range of technical elements: air washing and filtration of ventilation intake air from rooftop air handler, the use of an enclosed rooftop greenhouse with a high density of potted plants as a bio-filtration system, dedicated secondary HVAC/air handling units on each floor with re-circulating high efficiency filtration and UVC treatment of the heat exchanger coils, additional potted plants for bio-filtration on each floor, and a final exhaust via the restrooms located at each floor. The conditioned building exhaust air is passed through an energy recovery wheel and chemisorbent cartridge, transferring some heat to the incoming air to increase the HVAC energy efficiency. The management uses 'green' cleaning products exclusively in the building. Flooring is a combination of stone, tile and 'zero VOC' carpeting. Wood trim and finish appears to be primarily of solid sawn materials, with very little evidence of composite wood products. Furniture is likewise in large proportion constructed from solid wood materials. The overall impression is that of a very clean and well-kept facility. Surfaces are polished to a high sheen, probably with wax products. There was an odor of urinal ...
Date: April 27, 2010
Creator: Apte, Michael G. & Apte, Joshua S.
Partner: UNT Libraries Government Documents Department

Overcharge Protection for 4 V Lithium Batteries at High Rates and Low Temperature

Description: Overcharge protection for 4 V Li{sub 1.05}Mn{sub 1.95}O{sub 4}/lithium cells at charging rates in excess of 1 mA/cm{sup 2} (3C) and at temperatures as low as -20 C was achieved using a bilayer separator coated with two electroactive polymers. High rate and low temperature overcharge protection and discharge performance were improved by employing a design in which the polymer-coated portion of the separator is in parallel with the cell rather than between the electrodes. The effects of different membrane supports for the electroactive polymers are also examined.
Date: January 4, 2010
Creator: Chen, Guoying & Richardson, Thomas J.
Partner: UNT Libraries Government Documents Department

Exploration of Resource and Transmission Expansion Decisions in the Western Renewable Energy Zone Initiative

Description: Building transmission to reach renewable energy (RE) goals requires coordination among renewable developers, utilities and transmission owners, resource and transmission planners, state and federal regulators, and environmental organizations. The Western Renewable Energy Zone (WREZ) initiative brings together a diverse set of voices to develop data, tools, and a unique forum for coordinating transmission expansion in the Western Interconnection. In this report we use a new tool developed in the WREZ initiative to evaluate possible renewable resource selection and transmission expansion decisions. We evaluate these decisions under a number of alternative future scenarios centered on meeting 33% of the annual load in the Western Interconnection with new renewable resources located within WREZ-identified resource hubs. Of the renewable resources in WREZ resource hubs, and under the assumptions described in this report, our analysis finds that wind energy is the largest source of renewable energy procured to meet the 33% RE target across nearly all scenarios analyzed (38-65%). Solar energy is almost always the second largest source (14-41%). Solar exceeds wind by a small margin only when solar thermal energy is assumed to experience cost reductions relative to all other technologies. Biomass, geothermal, and hydropower are found to represent a smaller portion of the selected resources, largely due to the limited resource quantity of these resources identified within the WREZ-identified hubs (16-23% combined). We find several load zones where wind energy is the least cost resource under a wide range of sensitivity scenarios. Load zones in the Southwest, on the other hand, are found to switch between wind and solar, and therefore to vary transmission expansion decisions, depending on uncertainties and policies that affect the relative economics of each renewable option. Uncertainties and policies that impact bus-bar costs are the most important to evaluate carefully, but factors that impact transmission costs and the ...
Date: February 16, 2010
Creator: Mills, Andrew; Phadke, Amol & Wiser, Ryan
Partner: UNT Libraries Government Documents Department

Auto-DR and Pre-cooling of Buildings at Tri-City Corporate Center

Description: Over the several past years, Lawrence Berkeley National Laboratory (LBNL) has conducted field tests for different pre-cooling strategies in different commercial buildings within California. The test results indicated that pre-cooling strategies were effective in reducing electric demand in these buildings during peak periods. This project studied how to optimize pre-cooling strategies for eleven buildings in the Tri-City Corporate Center, San Bernardino, California with the assistance of a building energy simulation tool -- the Demand Response Quick Assessment Tool (DRQAT) developed by LBNL's Demand Response Research Center funded by the California Energy Commission's Public Interest Energy Research (PIER) Program. From the simulation results of these eleven buildings, optimal pre-cooling and temperature reset strategies were developed. The study shows that after refining and calibrating initial models with measured data, the accuracy of the models can be greatly improved and the models can be used to predict load reductions for automated demand response (Auto-DR) events. This study summarizes the optimization experience of the procedure to develop and calibrate building models in DRQAT. In order to confirm the actual effect of demand response strategies, the simulation results were compared to the field test data. The results indicated that the optimal demand response strategies worked well for all buildings in the Tri-City Corporate Center. This study also compares DRQAT with other building energy simulation tools (eQUEST and BEST). The comparison indicate that eQUEST and BEST underestimate the actual demand shed of the pre-cooling strategies due to a flaw in DOE2's simulation engine for treating wall thermal mass. DRQAT is a more accurate tool in predicting thermal mass effects of DR events.
Date: November 1, 2008
Creator: Yin, Rongxin; Xu, Peng & Kiliccote, Sila
Partner: UNT Libraries Government Documents Department

Demonstration of Datacenter Automation Software and Hardware (DASH) at the California Franchise Tax Board

Description: Control software and wireless sensors designed for closed-loop, monitoring and control of IT equipment's inlet air temperatures in datacenters were evaluated and tested while other datacenter cooling best practices were implemented. The controls software and hardware along with each best practice were installed sequentially and evaluated using a measurement and verification procedure between each measure. The results show that the overall project eliminates 475,239 kWh per year, which is 21.3percent of the baseline energy consumption of the data center. The total project, including the best practices will save $42,772 per year and cost $134,057 yielding a simple payback of 3.1 years. However, the control system alone eliminates 59.6percent of the baseline energy used to move air in the datacenter and 13.6percent of the baseline cooling energy, which is 15.2percent of the baseline energy consumption (see Project Approach, Task 1, below, for additional information) while keeping temperatures substantially within the limits recommended by ASHRAE. Savings attributed to the control system are $30,564 per year with a cost $56,824 for a simple payback of 1.9 years.
Date: December 18, 2009
Creator: Bell, Geoffrey C. & Federspiel, Clifford
Partner: UNT Libraries Government Documents Department

Impacts of Mixing on Acceptable Indoor Air Quality in Homes

Description: Ventilation reduces occupant exposure to indoor contaminants by diluting or removing them. In a multi-zone environment such as a house, every zone will have different dilution rates and contaminant source strengths. The total ventilation rate is the most important factor in determining occupant exposure to given contaminant sources, but the zone-specific distribution of exhaust and supply air and the mixing of ventilation air can play significant roles. Different types of ventilation systems will provide different amounts of mixing depending on several factors such as air leakage, air distribution system, and contaminant source and occupant locations. Most U.S. and Canadian homes have central heating, ventilation, and air conditioning systems, which tend to mix the air; thus, the indoor air in different zones tends to be well mixed for significant fractions of the year. This article reports recent results of investigations to determine the impact of air mixing on exposures of residential occupants to prototypical contaminants of concern. We summarize existing literature and extend past analyses to determine the parameters than affect air mixing as well as the impacts of mixing on occupant exposure, and to draw conclusions that are relevant for standards development and for practitioners designing and installing home ventilation systems. The primary conclusion is that mixing will not substantially affect the mean indoor air quality across a broad population of occupants, homes, and ventilation systems, but it can reduce the number of occupants who are exposed to extreme pollutant levels. If the policy objective is to minimize the number of people exposed above a given pollutant threshold, some amount of mixing will be of net benefit even though it does not benefit average exposure. If the policy is to minimize exposure on average, then mixing air in homes is detrimental and should not be encouraged. We also conclude that ...
Date: January 1, 2010
Creator: Sherman, Max H. & Walker, Iain I.
Partner: UNT Libraries Government Documents Department

Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine

Description: Neighbors living near the 3 turbine, 4.5 MW Vinalhaven, Maine wind power facility, which began operations in late 2009, have complained that the noise from the turbines is unwelcome and annoying. Fox Islands Wind, the owner of the facility, hypothesized that implementing a Noise Reduced Operation (NRO) for the turbines, which effectively limits the turbines maximum rpm and power output, would reduce the sound levels produced by the turbines, and therefore might also reduce the degree to which the neighbors report being annoyed by those sounds. To test this hypothesis in a preliminary fashion, a pilot study was conducted in early 2010, the results of which are the subject of this brief report. The study included asking near-by residents - those within roughly 3000 feet - to rate the sounds and the degree to which they were annoyed by them using logs which they filled out at multiple times during the day on as many days as were possible in the 35 day study period in February and March, 2010. Meanwhile, FIW adjusted the NRO settings of the turbines in a random fashion in the evenings during the same period, but in a pattern that the respondents were not made aware of. Ultimately, nine individuals turned in roughly 200 log entries (i.e., responses), each of which was time coded to allow testing if the response was correlated with the wind facility operating conditions at that time. The analysis of these data found small, non-statistically-significant differences in self-reported turbine loudness and annoyance ratings between the periods when the NRO was enacted and when it was not, after controlling for many of the relationships that could independently influence perceived loudness and annoyance (e.g., wind direction, time of day). Possible explanations for these small differences in self-reported turbine loudness and annoyance ratings include: ...
Date: June 23, 2010
Creator: Hoen, Ben; Wiser, Ryan & Eckholdt, Haftan
Partner: UNT Libraries Government Documents Department

Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

Description: With the current movement toward net zero energy buildings, many technologies are promoted with emphasis on their superior energy efficiency. The variable refrigerant flow (VRF) and ground source heat pump (GSHP) systems are probably the most competitive technologies among these. However, there are few studies reporting the energy efficiency of VRF systems compared with GSHP systems. In this article, a preliminary comparison of energy efficiency between the air-source VRF and GSHP systems is presented. The computer simulation results show that GSHP system is more energy efficient than the air-source VRF system for conditioning a small office building in two selected US climates. In general, GSHP system is more energy efficient than the air-source VRV system, especially when the building has significant heating loads. For buildings with less heating loads, the GSHP system could still perform better than the air-source VRF system in terms of energy efficiency, but the resulting energy savings may be marginal.
Date: November 1, 2009
Creator: Hong, Tainzhen & Liu, Xaiobing
Partner: UNT Libraries Government Documents Department

Financial Innovation Among the Community Wind Sector in the United States

Description: In the relatively brief history of utility-scale wind generation, the 'community wind' sector - defined here as consisting of relatively small utility-scale wind power projects that are at least partly owned by one or more members of the local community - has played a vitally important role as a 'test bed' or 'proving ground' for wind turbine manufacturers. In the 1980s and 1990s, for example, Vestas and other now-established European wind turbine manufacturers relied heavily on community wind projects in Scandinavia and Germany to install - and essentially field-test - new turbine designs. The fact that orders from community wind projects seldom exceeded more than a few turbines at a time enabled the manufacturers to correct any design flaws or manufacturing defects fairly rapidly, and without the risk of extensive (and expensive) serial defects that can accompany larger orders. Community wind has been slower to take root in the United States - the first such projects were installed in the state of Minnesota around the year 2000. Just as in Europe, however, the community wind sector in the U.S. has similarly served as a proving ground - but in this case for up-and-coming wind turbine manufacturers that are trying to break into the broader U.S. wind power market. For example, community wind projects have deployed the first U.S. installations of wind turbines from Suzlon (in 2003), DeWind (2008), Americas Wind Energy (2008) and later Emergya Wind Technologies (2010),1 Goldwind (2009), AAER/Pioneer (2009), Nordic Windpower (2010), Unison (2010), and Alstom (2011). Just as it has provided a proving ground for new turbines, so too has the community wind sector in the United States served as a laboratory for experimentation with innovative new financing structures. For example, a variation of one of the most common financing arrangements in the U.S. wind market ...
Date: January 19, 2011
Creator: Bolinger, Mark
Partner: UNT Libraries Government Documents Department

Max Tech and Beyond: Fluorescent Lamps

Description: Fluorescent lamps are the most widely used artificial light source today, responsible for approximately 70% of the lumens delivered to our living spaces globally. The technology was originally commercialized in the 1930's, and manufacturers have been steadily improving the efficacy of these lamps over the years through modifications to the phosphors, cathodes, fill-gas, operating frequency, tube diameter and other design attributes. The most efficient commercially available fluorescent lamp is the 25 Watt T5 lamp. This lamp operates at 114-116 lumens per watt while also providing good color rendering and more than 20,000 hours of operating life. Industry experts interviewed indicated that while this lamp is the most efficient in the market today, there is still a further 10 to 14% of potential improvements that may be introduced to the market over the next 2 to 5 years. These improvements include further developments in phosphors, fill-gas, cathode coatings and ultraviolet (UV) reflective glass coatings. The commercialization of these technology improvements will combine to bring about efficacy improvements that will push the technology up to a maximum 125 to 130 lumens per watt. One critical issue raised by researchers that may present a barrier to the realization of these improvements is the fact that technology investment in fluorescent lamps is being reduced in order to prioritize research into light emitting diodes (LEDs) and ceramic metal halide high intensity discharge (HID) lamps. Thus, it is uncertain whether these potential efficacy improvements will be developed, patented and commercialized. The emphasis for premium efficacy will continue to focus on T5 lamps, which are expected to continue to be marketed along with the T8 lamp. Industry experts highlighted the fact that an advantage of the T5 lamp is the fact that it is 40% smaller and yet provides an equivalent lumen output to that of a ...
Date: April 1, 2012
Creator: Scholand, Michael
Partner: UNT Libraries Government Documents Department

Max Tech and Beyond: High-Intensity Discharge Lamps

Description: High-intensity discharge (HID) lamps are most often found in industrial and commercial applications, and are the light source of choice in street and area lighting, and sports stadium illumination. HID lamps are produced in three types - mercury vapor (MV), high pressure sodium (HPS) and metal halide (MH). Of these, MV and MH are considered white-light sources (although the MV exhibits poor color rendering) and HPS produces a yellow-orange color light. A fourth lamp, low-pressure sodium (LPS), is not a HID lamp by definition, but it is used in similar applications and thus is often grouped with HID lamps. With the notable exception of MV which is comparatively inefficient and in decline in the US from both a sales and installed stock point of view; HPS, LPS and MH all have efficacies over 100 lumens per watt. The figure below presents the efficacy trends over time for commercially available HID lamps and LPS, starting with MV and LPS in 1930's followed by the development of HPS and MH in the 1960's. In HID lamps, light is generated by creating an electric arc between two electrodes in an arc tube. The particles in the arc are partially ionized, making them electrically conductive, and a light-emitting 'plasma' is created. This arc occurs within the arc tube, which for most HID lamps is enclosed within an evacuated outer bulb that thermally isolates and protects the hot arc tube from the surroundings. Unlike a fluorescent lamp that produces visible light through down-converting UV light with phosphors, the arc itself is the light source in an HID lamp, emitting visible radiation that is characteristic of the elements present in the plasma. Thus, the mixture of elements included in the arc tube is one critical factor determining the quality of the light emitted from the lamp, ...
Date: April 1, 2012
Creator: Scholand, Michael
Partner: UNT Libraries Government Documents Department

Measuring Advances in HVAC Distribution System Design

Description: Substantial commercial building energy savings have been achieved by improving the performance of the HV AC distribution system. The energy savings result from distribution system design improvements, advanced control capabilities, and use of variable-speed motors. Yet, much of the commercial building stock remains equipped with inefficient systems. Contributing to this is the absence of a definition for distribution system efficiency as well as the analysis methods for quantifying performance. This research investigates the application of performance indices to assess design advancements in commercial building thermal distribution systems. The index definitions are based on a first and second law of thermodynamics analysis of the system. The second law or availability analysis enables the determination of the true efficiency of the system. Availability analysis is a convenient way to make system efficiency comparisons since performance is evaluated relative to an ideal process. A TRNSYS simulation model is developed to analyze the performance of two distribution system types, a constant air volume system and a variable air volume system, that serve one floor of a large office building. Performance indices are calculated using the simulation results to compare the performance of the two systems types in several locations. Changes in index values are compared to changes in plant energy, costs, and carbon emissions to explore the ability of the indices to estimate these quantities.
Date: May 1, 1998
Creator: Franconi, E.
Partner: UNT Libraries Government Documents Department

Commissioning: A Highly Cost-Effective Building Energy Management Strategy

Description: Quality assurance and optimization are essential elements of any serious technological endeavor, including efforts to improve energy efficiency. Commissioning is an important tool in this respect. The aim of commissioning new buildings is to ensure that they deliver-if not exceed-the performance and energy savings promised by their design. When applied to existing buildings, one-time or repeated commissioning (often called retrocommissioning) identifies the almost inevitable drift in energy performance and puts the building back on course, often surpassing the original design intent. In both contexts, commissioning is a systematic, forensic approach to improving performance, rather than a discrete technology.
Date: January 6, 2011
Creator: Mills, Evan
Partner: UNT Libraries Government Documents Department

ENERGY EFFICIENT BUILDINGS PROGRAM. CHAPTER FROM THE ENERGY AND ENVIRONMENT DIVISION ANNUAL REPORT 1979

Description: The research reported in this volume was undertaken during FY 1979 within the Energy & Environment Division of the Lawrence Berkeley Laboratory. This volume will comprise a section of the Energy & Environment Division 1979 Annual Report, to be published in the summer of 1980. Work reported relate to: thermal performance of building envelopes; building ventilation and indoor air quality; a computer program for predicting energy use in buildings; study focused specifically on inherently energy intensive hospital buildings; energy efficient windows and lighting; potential for energy conservation and savings in the buildings sector; and evaluation of energy performance standards for residential buildings.
Date: December 1, 1979
Creator: Authors, Various
Partner: UNT Libraries Government Documents Department

ENERGY USE AND CONSERVATION IN INDUSTRIALIZED COUNTRIES

Description: One of the important aspects of America's painful adjustment to energy realities since 1973 has been an overwhelming effort to look carefully at how we use energy. Much to our surprise there was tremendous slack in energy use at home even before the Oil Embargo, slack that could have been eliminated profitably. One suggestion that there was waste in our economy came from careful inspection of energy use elsewhere. But early discussion of energy use in other lands has been marred by many distortions and misunderstandings, not only on the part of those who tend to doubt the potential for energy conservation but even among conservation's strongest supporters. This misunderstanding arises from comparisons of energy use and gross national product, two quantities that have charmed correlators and energy statisticians for decades. Though serious work cannot be based upon relationships between two such aggregated quantities, it is useful to review some of the popular myths surrounding energy comparisons among countries.
Date: November 1, 1978
Creator: Schipper, L.
Partner: UNT Libraries Government Documents Department