02807nas a2200253 4500008004100000022001300041245012200054210006900176260001200245300001100257490000800268520202500276653001602301653001902317653002402336653000802360653001202368100001402380700001802394700002102412700002502433700002802458856006702486 2019 eng d a0360132300aSplit-pane electrochromic window control based on an embedded photometric device with real-time daylighting computing0 aSplitpane electrochromic window control based on an embedded pho c08/2019 a1062290 v1613 a

Well-designed electrochromic (EC) glazing control can improve the energy performance of buildings and visual comfort of occupants in highly glazed buildings. This paper designed and demonstrated a compact integrated EC glazing automation system to control tint states of a split-pane EC window according to variations of sky conditions. The control is based on monitoring the luminance distribution of the sky and real-time lighting computation for a building interior, using an embedded photometric device (EPD). It optimizes tint states of EC glazing to offer sufficient daylight provision and temper discomfort glare for occupants, which potentially mitigates excessive solar heat gain. ’In-situ’ experiments were conducted in a full-scale testbed to demonstrate the daylighting performance under various sky conditions. Experimental results showed 83% of the working time for work-plane illuminance (WPI) and 95% of the time for daylight glare probability (DGP) were constrained in comfort range (WPI[500, 2000] lux, DGP  0.35) by the automated EC glazing (controlled by EPD) under clear skies; 68% of the time for WPI and 94% of the time for DGP in confined range under clear skies with thin clouds; 62% of the time for WPI and 85% of the time for DGP in confined range under partly cloudy skies.

10adaylighting10aelectrochromic10aEmbedded Controller10aHDR10awindows1 aWu, Yujie1 aWang, Taoning1 aLee, Eleanor, S.1 aKämpf, Jérôme, H.1 aScartezzini, Jean-Louis uhttps://linkinghub.elsevier.com/retrieve/pii/S036013231930439101940nas a2200169 4500008004100000050001500041245012400056210006900180300001200249490000700261520134000268100002201608700002301630700002001653700002801673856006901701 2005 eng d aLBNL-5881800aBi-Directional Transmission Properties of Venetian Blinds: Experimental Assessment Compared to Ray-Tracing Calculations0 aBiDirectional Transmission Properties of Venetian Blinds Experim a187-1980 v783 a

An accurate evaluation of daylight distribution through advanced fenestration systems (complex glazing, solar shading systems) requires the knowledge of their Bidirectional light Transmission (Reflection) Distribution Function BT(R)DF. An innovative equipment for the experimental assessment of these bi-directional functions has been developed, based on a digital imaging detection system. An extensive set of BTDF measurements was performed with this goniophotometer on Venetian blinds presenting curved slats with a mirror coating on the upper side. In this paper, the measured data are compared with ray-tracing results achieved with a virtual copy of the device, that was constructed with a commercial ray-tracing software. The model of the blind was created by implementing the measured reflection properties of the slats coatings in the ray-tracing calculations. These comparisons represent an original and objective validation methodology for detailed bi-directional properties for a complex system; the good agreement between the two methods, yet presenting very different parameters and assessment methodologies, places reliance both on the digital-imaging detection system and calibration, and on the potentiality of a flexible calculation method combining ray-tracing simulations with simple components measurements.

1 aAndersen, Marilyn1 aRubin, Michael, D.1 aPowles, Rebecca1 aScartezzini, Jean-Louis uhttps://facades.lbl.gov/publications/bi-directional-transmission02201nas a2200157 4500008004100000245011300041210006900154260001200223300001200235490000700247520164400254100002201898700002301920700002801943856007201971 2003 eng d00aComparison Between Ray-Tracing Simulations and Bi-Directional Transmission Measurements on Prismatic Glazing0 aComparison Between RayTracing Simulations and BiDirectional Tran c02/2003 a157-1730 v743 a

Evaluation of solar heat gain and daylight distribution through complex window and shading systems requires the determination of the bi-directional transmission distribution function (BTDF). Measurement of BTDF can be timeconsuming, and inaccuracies are likely because of physical constraints and experimental adjustments. A general calculation methodology, based on more easily measurable component properties, would be preferable and would allow much more flexibility. In this paper, measurements and calculations are compared for the specific case of prismatic daylight-redirecting panels. Measurements were performed in a photogoniometer equipped with a digital-imaging detection system. A virtual copy of the photogoniometer was then constructed with commercial ray-tracing software. For the first time, an attempt is made to validate detailed bi-directional properties for a complex system by comparing an extensive set of experimental BTDF data with ray-tracing calculations. The results generally agree under a range of input and output angles to a degree adequate for evaluation of glazing systems. An analysis is presented to show that the simultaneously measured diffuse and direct components of light transmitted by the panel are properly represented. Calculations were also performed using a more realistic model of the source and ideal model of the detector. Deviations from the photogoniometer model were small and the results were similar in form. Despite the lack of an absolute measurement standard, the good agreement in results promotes confidence in both the photogoniometer and in the calculation method. 

1 aAndersen, Marilyn1 aRubin, Michael, D.1 aScartezzini, Jean-Louis uhttps://facades.lbl.gov/publications/comparison-between-ray-tracing00811nam a2200241 4500008004100000050001500041245007900056210006900135100001600204700002300220700001900243700002500262700002000287700001700307700002000324700003000344700002000374700002100394700002000415700002800435700002700463856007900490 2001 eng d aLBNL-4749300aDaylight in Buildings. A Source Book on Daylighting Systems and Components0 aDaylight in Buildings A Source Book on Daylighting Systems and C1 aRuck, Nancy1 aAschehoug, Øyvind1 aAydinli, Sirri1 aChristoffersen, Jens1 aCourret, Gilles1 aEdmonds, Ian1 aJakobiak, Roman1 aKischkoweit-Lopin, Martin1 aKlinger, Martin1 aLee, Eleanor, S.1 aMichel, Laurent1 aScartezzini, Jean-Louis1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/daylight-buildings-source-book-daylighting-systems