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Title: Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames

Abstract

While window frames typically represent 20-30percent of the overall window area, their impact on the total window heat transfer rates may be much larger. This effect is even greater in low-conductance (highly insulating) windows which incorporate very low conductance glazings. Developing low-conductance window frames requires accurate simulation tools for product research and development. The Passivhaus Institute in Germany states that windows (glazing and frames, combined) should have U-values not exceeding 0.80 W/(m??K). This has created a niche market for highly insulating frames, with frame U-values typically around 0.7-1.0 W/(m2 cdot K). The U-values reported are often based on numerical simulations according to international simulation standards. It is prudent to check the accuracy of these calculation standards, especially for high performance products before more manufacturers begin to use them to improve other product offerings. In this paper the thermal transmittance of five highly insulating window frames (three wooden frames, one aluminum frame and one PVC frame), found from numerical simulations and experiments, are compared. Hot box calorimeter results are compared with numerical simulations according to ISO 10077-2 and ISO 15099. In addition CFD simulations have been carried out, in order to use the most accurate tool available to investigate the convectionmore » and radiation effects inside the frame cavities. Our results show that available tools commonly used to evaluate window performance, based on ISO standards, give good overall agreement, but specific areas need improvement.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
Environmental Energy Technologies Division
OSTI Identifier:
988080
Report Number(s):
LBNL-3886E
TRN: US201018%%237
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Conference
Resource Relation:
Conference: Thermal Performance of the Exterior Envelopes of Whole Buildings XI International Conference, Clearwater Beach, FL, December 5-9, 2010
Country of Publication:
United States
Language:
English
Subject:
32; ACCURACY; ALUMINIUM; CALORIMETERS; CAVITIES; CONVECTION; GLAZING MATERIALS; HEAT TRANSFER; MANUFACTURERS; MARKET; PERFORMANCE; RADIATION EFFECTS; SIMULATION; U VALUES; WINDOW FRAMES; WINDOWS; Fenestration, window frames, heat transfer modeling, U-value, thermal transmittance, frame cavity, international standards, hot box, experimental

Citation Formats

Gustavsen Ph D, Arild, Goudey, Howdy, Kohler, Christian, Arasteh P E, Dariush, Uvslokk, Sivert, Talev, Goce, and Petter Jelle Ph.D., Bjorn. Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames. United States: N. p., 2010. Web.
Gustavsen Ph D, Arild, Goudey, Howdy, Kohler, Christian, Arasteh P E, Dariush, Uvslokk, Sivert, Talev, Goce, & Petter Jelle Ph.D., Bjorn. Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames. United States.
Gustavsen Ph D, Arild, Goudey, Howdy, Kohler, Christian, Arasteh P E, Dariush, Uvslokk, Sivert, Talev, Goce, and Petter Jelle Ph.D., Bjorn. 2010. "Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames". United States. https://www.osti.gov/servlets/purl/988080.
@article{osti_988080,
title = {Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames},
author = {Gustavsen Ph D, Arild and Goudey, Howdy and Kohler, Christian and Arasteh P E, Dariush and Uvslokk, Sivert and Talev, Goce and Petter Jelle Ph.D., Bjorn},
abstractNote = {While window frames typically represent 20-30percent of the overall window area, their impact on the total window heat transfer rates may be much larger. This effect is even greater in low-conductance (highly insulating) windows which incorporate very low conductance glazings. Developing low-conductance window frames requires accurate simulation tools for product research and development. The Passivhaus Institute in Germany states that windows (glazing and frames, combined) should have U-values not exceeding 0.80 W/(m??K). This has created a niche market for highly insulating frames, with frame U-values typically around 0.7-1.0 W/(m2 cdot K). The U-values reported are often based on numerical simulations according to international simulation standards. It is prudent to check the accuracy of these calculation standards, especially for high performance products before more manufacturers begin to use them to improve other product offerings. In this paper the thermal transmittance of five highly insulating window frames (three wooden frames, one aluminum frame and one PVC frame), found from numerical simulations and experiments, are compared. Hot box calorimeter results are compared with numerical simulations according to ISO 10077-2 and ISO 15099. In addition CFD simulations have been carried out, in order to use the most accurate tool available to investigate the convection and radiation effects inside the frame cavities. Our results show that available tools commonly used to evaluate window performance, based on ISO standards, give good overall agreement, but specific areas need improvement.},
doi = {},
url = {https://www.osti.gov/biblio/988080}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2010},
month = {6}
}

Conference:
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