[PDF] Buildings Research Using Infrared Imaging Radiometers With Laboratory Thermal Chambers eBook

Author :
Publisher :
Page : 17 pages
File Size : 26,13 MB
Release : 1999
Category :
ISBN :

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Infrared thermal imagers are used at Lawrence Berkeley National Laboratory to study heat transfer through components of building thermal envelopes. Two thermal chambers maintain steady-state heat flow through test specimens under environmental conditions for winter heating design. Infrared thermography is used to map surface temperatures on the specimens' warm side. Features of the quantitative thermography process include use of external reference emitters, complex background corrections, and spatial location markers. Typical uncertainties in the data are " 0.5 C and 3 mm. Temperature controlled and directly measured external reference emitters are used to correct data from each thermal image. Complex background corrections use arrays of values for background thermal radiation in calculating temperatures of self-viewing surfaces. Temperature results are used to validate computer programs that predict heat flow including Finite-Element Analysis (FEA) conduction simulations and conjugate Computational Fluid Dynamics (CFD) simulations. Results are also used to study natural convection surface heat transfer. Example data show the distribution of temperatures down the center line of an insulated window.

Author : DK. Arasteh
Publisher :
Page : 23 pages
File Size : 33,1 MB
Release : 1997
Category : Computer model validation
ISBN :

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Infrared (IR) imaging radiometers, which measure relative levels of thermal radiation energy, can be used for noninvasive surface temperature measurements of building thermal envelope components undergoing steady-state heat flow in laboratory thermal chambers. One advantage of IR measurement is that it provides large contiguous sets of surface temperature data which are useful for validating the accuracy of complex computer models that predict heat flow through thermally insulated systems. Because they give such detailed information about surface temperature, IR measurements complement hot-box measurements of heat flow. This paper recommends general procedures for reliable quantitative thermographic measurements in chambers operated for winter heating conditions. Actual surface temperature depends on heat flow, surface emittance, and environmental conditions such as air temperature, air flow field, and background thermal radiation. The infrared temperature measurements are affected by many of the same factors including surface emittance, air temperature, background thermal radiation, and air humidity. Equipment specifications for the absolute accuracy of infrared temperature measurements are typically ±1° to ±2°C. Measurements that use a temperature-controlled reference emitter to remove error appear to show accuracies of ±0.5°C for flat specimens with low temperature gradients.

Author : Xavier Maldague
Publisher : Wiley-Interscience
Page : 716 pages
File Size : 47,21 MB
Release : 2001-04-30
Category : Business & Economics
ISBN :

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The book includes fundamental concepts of theory, instrumentation, and experimental practice as well as practical applications. An important chapter setting the book apart from other publications describes the properties of materials and presents case studies from industry. In addition, a program called IRNDT accompanies the book and is available on the Wiley ftp site. The program includes an image bank that can be used to test the principles covered in the book. * All chapters end with summaries, problems, and questions. * Authored by an acknowledged expert in the field. * Material draws on case studies to illustrate major points.

Author : John Carmody
Publisher : W. W. Norton & Company
Page : 236 pages
File Size : 20,62 MB
Release : 2000
Category : Architecture
ISBN : 9780393730531

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This edition covers every aspect of window design and technology and includes a much-expanded sextion on energy performance, with an extended list of climate zones and glazing options.

Author : John Carmody
Publisher : W. W. Norton & Company
Page : 260 pages
File Size : 21,75 MB
Release : 2007-06-26
Category : Architecture
ISBN : 9780393732252

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or more locations.

Author : Ronald S. Graves
Publisher : ASTM International
Page : 541 pages
File Size : 14,94 MB
Release : 1997
Category : Insulating materials
ISBN : 0803124090

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...Contains papers presented at the Third Symposium on Insulation Materials: Testing and Applications, held in Quebec City, Quebec, Canada, on 15-17 May 1997.

Author : Richard H. Munis
Publisher :
Page : 26 pages
File Size : 43,51 MB
Release : 1977
Category : Buildings
ISBN :

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A heat loss survey was performed on five typical Air Force Base buildings with an infrared camera system: two with wood frames and wood clapboards, one with wood frame and aluminum siding, and two of cinder block construction with brick veneer. A walk-through inspection was also performed on three of these buildings chosen by project monitors for retrofitting. This report presents thermograms typical of the heat loss problems in each of the five buildings along with a complete explanation of each thermogram. The purpose of the report is to serve as a basis upon which Air Force civil engineers can plan a future retrofit program for the buildings surveyed and write a set of specifications incorporating thermography. Typical thermograms show heat loss from large, single-pane, steel-frame, projected windows, which in one building account for 50% of the total wall area. Infiltration losses through framing spaces for all windows are evident. Heat patterns from precast concrete floor slabs and radiators under the windows showed up clearly. Ribs in uninsulated door panels were clearly seen as well as leakage around the doors. Heat loss through the roof of a one-story duplex was easily recorded from the ground using the infrared camera system. Thermographic comparisons between windows with storm sashes and a picture window insulating glass were made. Heat was found escaping from slab foundation vents and gable vents. (Author).

Author : Mohammed Abdul Waheed Khan
Publisher : LAP Lambert Academic Publishing
Page : 160 pages
File Size : 39,98 MB
Release : 2015-11-17
Category :
ISBN : 9783659806865

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Infrared thermography is an important and powerful technique for diagnostics and evaluation of building envelope, in terms of locating thermal bridges, damaged thermal insulation, air leakage, moisture damage, and cracks, all of which contribute to an increase in the energy consumption of the buildings. This is because typically the thermal gains or losses in practice are greater than those estimated during the design stage. Accurate and detailed information of where a problem occurs can reveal the source of the problem thus avoiding extensive renovation work and hence decreasing the cost of repair work and potential energy savings can be achieved. The present study is aimed at assessing the effective R-value of building envelope, using high definition thermal imaging technique.