Overview of a Project to Determine the Surface Temperatures of Insulated Glazing Units: Thermographic Measurement and Two-Dimensional Simulation

© 1996. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions, Vol. 102, Part 2. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE’s prior written permission.A collaborative research project was undertaken to generate surface temperature profiles for the indoor side of seven different double and triple-glazed insulated glazing units exposed to the ASHRAE winter design condition. Four research groups produced four sets of results in a blind study. Two sets were measured by means of thermography and two were generated using two-dimensional numerical simulation. In addition, each simulation group produced results using simplified methods. Companion papers each present results from the individual studies along with some observations and commentary. This paper, an overview, presents a compilation of results and provides the opportunity for a variety of comparisons. Good agreement was found among all four sets of data. Simplified simulation models also show promise. The reassurance offered by these accomplishments is important because both the measurement and simulation methods are in the early stages of development. In addition, details found in individual temperature profiles provide valuable insights regarding the mechanisms of window heat transfer.Natural Resources Canada || Natural Sciences and Engineering Research Council || Assistant Secretary for Conservation and Renewable Energy || Office of Buildings and Community Systems || Building Systems Division of the U.S. Department of Energy || The University of Massachusett

Thermal Remote Sensing and the Thermodynamics of Ecosystem Development

Ecosystems develop structure and function that degrades the quality of the incoming energy more effectively. The ecosystem T and Rn/K* and TRN are excellent candidates for indicators of ecological integrity. The potential for these methods to be used for remote sensed ecosystem classification and ecosystem health/integrity evaluation is apparen

A study of insulated glazing unit surface temperature profiles using two-dimensional computer simulation

© 1996. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Published in ASHRAE Transactions, Vol. 102, Part 2. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE’s prior written permission.This paper describes one part of a collaborative research project, including both measurement and simulation studies, aimed at determining the surface temperature of a set of insulated glazing units (IGUs). In this study computer simulation was used to determine the vertical surface temperature profiles of seven air-filled glazing units. Glazing system design options included variations in edge-seal type, pane spacing, low-e coating, and number of glazings. Two approaches were taken: one, a simulation of the complete problem domain using a fully detailed two-dimensional numerical simulation program (BRAVO); the second, a simplified approach using the VISION4 program for one-dimensional center-glass analysis and the FRAME 4.0 program for analysis of the remaining sections. This study serves as an important step in the development of alternative methods for evaluating condensation resistance. The present study significantly extends the database of two-dimensional simulation results. Details regarding the other parts of this project can also be found in the literature.CANMET (Natural Resources Canada || Natural Sciences and Engineering Research Council of Canad

Thermal Remote Sensing and the Thermodynamics of Ecosystem Development

No abstract availabl

Thermal Remote Sensing and the Thermodynamics of Ecosystem Development

Thermal remote sensing can provide environmental measuring tools with capabilities for measuring ecosystem development and integrity. Recent advances in applying principles of nonequilibrium thermodynamics to ecology provide fundamental insights into energy partitioning in ecosystems. Ecosystems are nonequilibrium systems, open to material and energy flows, which grow and develop structures and processes to increase energy degradation. More developed terrestrial ecosystems will be more effective at dissipating the solar gradient (degrading its exergy content) and can be measured by the effective surface temperature of the ecosystem on a landscape scale. Ecosystems are viewed as open thermodynamic systems with a large gradient impressed on them by the exergy flux from the sun. Ecosystems, according to the restated second law, develop in ways that systematically increases their ability to degrade the incoming solar exergy, hence negating it's ability to set up even larger gradients. Thus it should be expected that more mature ecosystems degrade the exergy they capture more completely than a less developed ecosystem. The degree to which incoming solar exergy is degraded is a function of the surface temperature of the ecosystem. If a group of ecosystems receives the same amount of incoming radiation, we would expect that the most mature ecosystem would reradiate its energy at the lowest quality level and thus would have the lowest surface temperature (coldest black body temperature). Initial development work was done using NASA's airborne Thermal Infrared Multispectral Scanner (TIMS) followed by the use of a multispectral visible and thermal scanner-Airborne Thermal and Land Applications Sensor (ATLAS). Luvall and his coworkers have documented ecosystem energy budgets, including tropical forests, midlatitude varied ecosystems, and semiarid ecosystems. These data show that under similar environmental conditions (air temperature, relative humidity, winds, and solar irradiance) and within a given biome type, the more developed the ecosystem, the cooler it's surface temperature and the more degraded the quality of it's reradiated energy. HyspIRI is a hyperspectral visible/Near IR and multispectral thermal future global satellite mission that will collect data to study the world's ecosystems and will provide a benchmark on the state of the worlds ecosystems against which future changes can be assessed. HyspIRI will provide global data sets that will provide a means for measuring ecosystem development and integrity

Thermal Remote Sensing and the Thermodynamics of Ecosystem Development

Thermal remote sensing can provide environmental measuring tools with capabilities for measuring ecosystem development and integrity. Recent advances in applying principles of nonequilibrium thermodynamics to ecology provide fundamental insights into energy partitioning in ecosystems. Ecosystems are nonequilibrium systems, open to material and energy flows, which grow and develop structures and processes to increase energy degradation. More developed terrestrial ecosystems will be more effective at dissipating the solar gradient (degrading its exergy content) and can be measured by the effective surface temperature of the ecosystem on a landscape scale. Ecosystems are viewed as open thermodynamic systems with a large gradient impressed on them by the exergy flux from the sun. Ecosystems, according to the restated second law, develop in ways that systematically increases their ability to degrade the incoming solar exergy, hence negating it's ability to set up even larger gradients. Thus it should be expected that more mature ecosystems degrade the exergy they capture more completely than a less developed ecosystem. The degree to which incoming solar exergy is degraded is a function of the surface temperature of the ecosystem. If a group of ecosystems receives the same amount of incoming radiation, we would expect that the most mature ecosystem would reradiate its energy at the lowest quality level and thus would have the lowest surface temperature (coldest black body temperature). Initial development work was done using NASA's airborne Thermal Infrared Multispectral Scanner (TIMS) followed by the use of a multispectral visible and thermal scanner- Airborne Thermal and Land Applications Sensor (ATLAS). Luvall and his coworkers have documented ecosystem energy budgets, including tropical forests, midlatitude varied ecosystems, and semiarid ecosystems. These data show that under similar environmental conditions (air temperature, relative humidity, winds, and solar irradiance) and within a given biome type, the more developed the ecosystem, the cooler it's surface temperature and the more degraded the quality of it's reradiated energy. HyspIRI is a hyperspectral visible/Near IR and multispectral thermal future global satellite mission that will collect data to study the world's ecosystems and will provide a benchmark on the state of the worlds ecosystems against which future changes can be assessed. HyspIRI will provide global data sets that will provide a means for measuring ecosystem development and integrity