01962nas a2200169   4500008004100000050001500041245010000056210006900156260003100225490001600256520135300272100002401625700002901649700002101678700002501699856006801724       1997                        eng d  aLBNL-4069000aThe Significance of Bolts in the Thermal Performance of Curtain-Wall Frames for Glazed Façades0 aSignificance of Bolts in the Thermal Performance of CurtainWall   aSan Francisco, CAc01/19980 v104, Part 13 a<p>Curtain walls are assemblies of glazings and metal frames that commonly form the exterior glass façades of commercial buildings. Evaluating the thermal performance of the bolts that hold curtain wall glazings in place is necessary to accurately rate the overall thermal performance of curtain walls. Using laboratory tests and computer simulations, we assessed the thermal performance of several different configurations of bolts and glazings. Curtain-wall samples were tested in the infrared thermography laboratory at the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California. Experimental results were compared to two-dimensional simulations approximating the thermal effect of the bolts using the parallel path and the isothermal planes calculation methods. We conclude that stainless steel bolts minimally affect curtain-wall thermal performance (approximately 18%) when spaced at least nine inches apart, which is the industry standard. Performance is increasingly compromised when there is less than nine inches between bolts or when steel bolts are used. We also show that the isothermal planes method of approximating curtain wall thermal performance can be used with 2-D heat transfer software typical of that used in the window industry to give conservative results for the thermal bridging effect caused by bolts.</p>1 aGriffith, Brent, T.1 aFinlayson, Elizabeth, U.1 aYazdanian, Mehry1 aArasteh, Dariush, K.  uhttps://facades.lbl.gov/publications/significance-bolts-thermal01611nas a2200157   4500008004100000024001100041245009900052210006900151260001200220490000800232520107300240100002401313700001901337700002501356856007201381       1995                        eng d  aTA-35200aSurface Temperatures of Insulated Glazing Units: Infrared Thermography Laboratory Measurements0 aSurface Temperatures of Insulated Glazing Units Infrared Thermog  c12/19950 v1023 a<p>Data are presented for the distribution of surface temperatures on the warm-side surface of seven different insulated glazing units. Surface temperatures are measured using infrared thermography and an external referencing technique. This technique allows detailed mapping of surface temperatures that is non-intrusive. The glazings were placed between warm and cold environmental chambers that were operated at conditions corresponding to standard design conditions for winter heating. The temperatures conditions are 21.1 °C (70 °F) and -17.8 °C (0 °F) on the warm and cold sides, respectively. Film coefficients varied somewhat with average conditions of about 7.6 W/m<sup>2</sup> K (1.34 Btu/h ft<sup>2</sup> °F) for the warm-side and 28.9 W/m<sup>2</sup> K (5.1 Btu/h ft<sup>2</sup> °F) for the cold-side. Surface temperature data are plotted for the vertical distribution along the centerline of the IG and for the horizontal distribution along the centerline. This paper is part of larger collaborative effort that studied the same set of glazings.</p>1 aGriffith, Brent, T.1 aTurler, Daniel1 aArasteh, Dariush, K.  uhttps://facades.lbl.gov/publications/surface-temperatures-insulated