01691nas a2200169 4500008004100000050001500041245008300056210006900139300001200208490000700220520112600227100002501353700003401378700001401412700002401426856007101450 2001 eng d aLBNL-4901800aA Method for Simulating the Performance of Photosensor-Based Lighting Controls0 aMethod for Simulating the Performance of PhotosensorBased Lighti a883-8890 v343 a

The unreliability of photosensor-based lighting controls continues to be a significant market barrier that prevents widespread acceptance of daylight dimming controls in commercial buildings. Energy savings from the use of daylighting in commercial buildings is best realized through the installation of reliable photoelectric lighting controls that dim electric lights when sufficient daylight is available to provide adequate background and/or task illumination. In prior work, the authors discussed the limitations of current simulation approaches and presented a robust method to simulate the performance of photosensor-based controls using an enhanced version of the radiance lighting simulation package. The method is based on the concept of multiplying two fisheye images: one generated from the angular sensitivity of the photosensor and the other from a 180 or 360 deg. fisheye image of the space as seen by the photosensor. This paper includes a description of the method, its validation and possible applications for designing, placing, calibrating and commissioning photosensor-based lighting controls.

1 aEhrlich, Charles, K.1 aPapamichael, Konstantinos, M.1 aLai, Judy1 aRevzan, Kenneth, L. uhttps://facades.lbl.gov/publications/method-simulating-performance01681nas a2200157 4500008004100000050001500041245006800056210006700124260003600191520112500227100002501352700003401377700001401411700002401425856007401449 2001 eng d aLBNL-4754400aSimulating the Operation of Photosensor-Based Lighting Controls0 aSimulating the Operation of PhotosensorBased Lighting Controls aRio de Janeiro, Brazilc08/20013 a

Energy savings from the use of daylighting in commercial buildings are realized through implementation of photoelectric lighting controls that dim electric lights when sufficient daylight is available to provide adequate workplane illumination. The dimming level of electric lighting is based on the signal of a photosensor. Current simulation approaches for such systems are based on the questionable assumption that the signal of the photosensor is proportional to the task illuminance. This paper presents a method that simulates the performance of photosensor controls considering the acceptance angle, angular sensitivity, placement of the photosensor within a space, and color correction filter. The method is based on the multiplication of two fisheye images: one generated from the angular sensitivity of the photosensor and the other from a 180- or 360-degree fisheye image of the space as seen by the photosensor. The paper includes a detailed description of the method and its implementation, example applications, and validation results based on comparison with measurements in an actual office space.

1 aEhrlich, Charles, K.1 aPapamichael, Konstantinos, M.1 aLai, Judy1 aRevzan, Kenneth, L. uhttps://facades.lbl.gov/publications/simulating-operation-photosensor02919nas a2200169 4500008004100000050001500041245008000056210006900136260002200205300001200227490000600239520235300245100003402598700001802632700002402650856007502674 1997 eng d aLBNL-4059100aBuilding Design Advisor: Automated Integration of Multiple Simulation Tools0 aBuilding Design Advisor Automated Integration of Multiple Simula bElsevierc08/1997 a341-3520 v63 a

The Building Design Advisor (BDA) is a software environment that supports the integrated use of multiple analysis and visualization tools throughout the building design process, from the initial, conceptual and schematic phases to the detailed specification of building components and systems. Based on a comprehensive design theory, the BDA uses an object-oriented representation of the building and its context, and acts as a data manager and process controller to allow building designers to benefit from the capabilities of multiple tools.

The BDA provides a graphical user interface that consists of two main elements: the Building Browser and the Decision Desktop. The Browser allows building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to multiple descriptive and performance parameters addressed by the tools linked to the BDA.

The BDA is implemented as a Windows®-based application for personal computers. Its initial version is linked to a Schematic Graphic Editor (SGE), which allows designers to quickly and easily specify the geometric characteristics of building components and systems. For every object created in the SGE, the BDA activates a Default Value Selector (DVS) mechanism that selects "smart" default values from a Prototypes Database for all non-geometric parameters required as input to the analysis and visualization tools linked to the BDA. In addition to the SGE that is an integral part of its user interface, the initial version of the BDA is linked to a daylight analysis tool, an energy analysis tool, and a multimedia, Web-based Case Studies Database (CSD). The next version of the BDA will be linked to additional analysis tools, such as the DOE-2 (thermal, energy and energy cost) and RADIANCE (day/lighting and rendering) computer programs. Plans for the future include the development of links to cost estimating and environmental impact modules, building rating systems, CAD software and electronic product catalogs.

1 aPapamichael, Konstantinos, M.1 aLaPorta, John1 aChauvet, Hannah, L. uhttps://facades.lbl.gov/publications/building-design-advisor-automated02680nas a2200181 4500008004100000245003200041210002800073260002400101520214100125100003402266700001802300700002402318700002102342700002202363700002102385700002702406856006502433 1996 eng d00aThe Building Design Advisor0 aBuilding Design Advisor aTucson, AZc03/19963 a

The Building Design Advisor (BDA) is a software environment that supports the integrated use of multiple analysis and visualization tools throughout the building design process, from the initial, schematic design phases to the detailed specification of building components and systems. Based on a comprehensive design theory, the BDA uses an object-oriented representation of the building and its context, and acts as a data manager and process controller to allow building designers to benefit from the capabilities of multiple tools. The BDA provides a graphical user interface that consists of two main elements: the Building Browser and the Decision Desktop. The Browser allows building designers to quickly navigate through the multitude of descriptive and performance parameters addressed by the analysis and visualization tools linked to the BDA. Through the Browser the user can edit the values of input parameters and select any number of input and/or output parameters for display in the Decision Desktop. The Desktop allows building designers to compare multiple design alternatives with respect to any number of parameters addressed by the tools linked to the BDA. The BDA is implemented as a Windows™-based application for personal computers. Its initial version is linked to a Schematic Graphic Editor (SGE), which allows designers to quickly and easily specify the geometric characteristics of building components and systems. For every object created in the SGE, the BDA supplies モsmartヤ default values from a Prototypical Values Database (PVD) for all non-geometric parameters required as input to the analysis and visualization tools linked to the BDA. In addition to the SGE and the PVD, the initial version of the BDA is linked to a daylight analysis tool, an energy analysis tool, and a multimedia Case Studies Database (CSD). The next version of the BDA will be linked to additional tools, such as a photo-accurate rendering program and a cost analysis program. Future versions will address the whole building life-cycle and will be linked to construction, commissioning and building monitoring tools.

1 aPapamichael, Konstantinos, M.1 aLaPorta, John1 aChauvet, Hannah, L.1 aCollins, Deirdre1 aTrzcinski, Thomas1 aThorpe, Jack, A.1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/building-design-advisor02117nas a2200133 4500008004100000050001500041245007800056210006900134520162400203100003401827700002501861700002201886856007501908 1996 eng d aLBNL-4416700aDesign and Evaluation of Daylighting Applications of Holographic Glazings0 aDesign and Evaluation of Daylighting Applications of Holographic3 a

When combined with appropriate electric lighting dimming controls, the use of daylight for ambient and task illumination can significantly reduce energy requirements in commercial buildings. While skylights can effectively illuminate any part of one-story buildings, conventional side windows can illuminate only a 15 ft - 20 ft (4.6 m - 6.1 m) depth of the building perimeter. Even so, the overall efficacy of daylight is limited, because side windows produce uneven distributions of daylight. Achieving adequate illumination at distances further away from the window results in excessive illumination near the window, which increases cooling loads from the associated solar heat gain. As a result, the use of larger apertures and/or higher transmittance glazings, to introduce daylight deeper than 15 ft - 20 ft (4.6 m - 6.1 m), may prove ineffective with respect to saving energy, because cooling load penalties may exceed the electric lighting savings.

The need for more uniform distribution of daylight admitted through side windows has stimulated significant research and development efforts in new fenestration designs and glazing technologies. Many of these approaches, including holographic glazings, rely on the common strategy of redirecting sunlight and reflecting it off the ceiling towards the back of the room. Prior studies on the daylight and energy performance of holographic glazings have been disappointing, however inconclusive because of poor hologram quality, low diffraction efficiency and inadequate hologram design and building application considerations [Papamichael et al 1994].

1 aPapamichael, Konstantinos, M.1 aEhrlich, Charles, K.1 aWard, Gregory, J. uhttps://facades.lbl.gov/publications/design-and-evaluation-daylighting01829nas a2200157 4500008004100000050001400041245011000055210006900165260002600234520122600260100002501486700002101511700003401532700002701566856007801593 1994 eng d aLBL-3445800aThe Design and Evaluation of Three Advanced Daylighting Systems: Light Shelves, Light Pipes and Skylights0 aDesign and Evaluation of Three Advanced Daylighting Systems Ligh aSan Jose, CAc06/19943 a

We present results from the design and evaluation of three advanced daylighting systems: a light shelf, a light pipe, and a skylight. These systems use optical films and an optimizedsgeometry to passively intercept and redirect sunlight further into the building. The objectives of these designs are to increase daylighting illuminance levels at distances of 4.6-9.1 m (15-30 ft) from the window, and to improve the uniformity of the daylight distribution and the luminance gradient across the room under variable sun and sky conditions throughout the year. The designs were developed through a series of computer-assisted ray-tracing studies, photometric measurements, and observations using physical scale models. Comprehensive sets of laboratory measurements in combination with analytical routines were then used to simulate daylight performance for any solar position. Results show increased daylight levels and an improved luminance gradient throughout the year - indicating that lighting energy consumption and cooling energy due to lighting can be substantially reduced with improvements to visual comfort. Future development of the designs may further improve the daylighting performance of these systems.

1 aBeltran, Liliana, O.1 aLee, Eleanor, S.1 aPapamichael, Konstantinos, M.1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/design-and-evaluation-three-advanced02425nas a2200169 4500008004100000024001100041245009500052210006900147260003100216520180500247100002102052700002102073700003402094700002302128700002702151856007702178 1994 eng d aUC-35000aEffect of Switching Control Strategies on the Energy Performance of Electrochromic Windows0 aEffect of Switching Control Strategies on the Energy Performance aFreiburg, Germanyc04/19943 a

This paper presents the results of a study investigating the energy performance of electrochromic windows under a variety of state-switching control strategies. We used the DOE-2.1E energy simulation program to analyze the annual cooling, lighting, and total electricity use and peak demand as a function of glazing type, size, and electrochromic control strategy. We simulated a prototypical commercial office building module located in the cooling-dominated location of Blythe, California. Control strategies analyzed were based on daylight illuminance, incident total solar radiation, and space cooling load. Our results show that when a daylighting strategy is used to reduce electric lighting requirements, control algorithms based on daylight illuminance results in the best overall annual energy performance. If daylighting is not an design option, controls based on space cooling load yield the best performance through solar heat gain reduction. The performance of incident total solar radiation control strategies varies as a function of the switching setpoints; for small to moderate window sizes which result in small to moderate solar gains, a large setpoint-range was best since it provides increased illuminance for daylighting without much cooling penalty; for larger window sizes, which provide adequate daylight, a smaller setpoint-range was best to reduce unwanted solar heat gains and the consequential increased cooling requirement. Of particular importance is the fact that reduction in peak electric demand was found to be independent of the type of control strategy used for electrochromic switching. This is because the electrochromics are generally in their most colored state under peak conditions, and the mechanism used for achieving such a state is not important.

1 aSullivan, Robert1 aLee, Eleanor, S.1 aPapamichael, Konstantinos, M.1 aRubin, Michael, D.1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/effect-switching-control-strategies02740nas a2200181 4500008004100000050001900041245006200060210006200122260003100184520212100215100003402336700002502370700002102395700002102416700002702437700002302464856007102487 1994 eng d aLBL-35382 Rev.00aSimulating the Energy Performance of Holographic Glazings0 aSimulating the Energy Performance of Holographic Glazings aFreiburg, Germanyc04/19943 a

The light diffraction properties of holographic diffractive structures present an opportunity to improve the daylight performance in side-lit office spaces by redirecting and reflecting sunlight off the ceiling, providing adequate daylight illumination up to 30 ft (9.14 m) from the window wall. Prior studies of prototypical holographic glazings, installed above conventional view windows, have shown increased daylight levels over a deeper perimeter area than clear glass, for selected sun positions. In this study, we report on the simulation of the energy performance of prototypical holographic glazings assuming a commercial office building in the inland Los Angeles climate.

The simulation of the energy performance involved determination of both luminous and thermal performance. Since the optical complexity of holographic glazings prevented the use of conventional algorithms for the simulation of their luminous performance, we used a newly developed method that combines experimentally determined directional workplane illuminance coefficients with computer-based analytical routines to determine a comprehensive set of daylight factors for many sun positions. These daylight factors were then used within the DOE-2.1D energy simulation program to determine hourly daylight and energy performance over the course of an entire year for four window orientations.

Since the prototypical holographic diffractive structures considered in this study were applied on single pane clear glass, we also simulated the performance of hypothetical glazings, assuming the daylight performance of the prototype holographic glazings and the thermal performance of double-pane and low-e glazings. The results of our analyses show that these prototypical holographic glazings did not save significant electric energy or reduce peak electricity demand compared to conventional energy-efficient window systems in inland Los Angeles office buildings, mainly because of their low diffraction efficiency. Finally, we address various design and implementation issues towards potential performance improvement.

1 aPapamichael, Konstantinos, M.1 aBeltran, Liliana, O.1 aFurler, Reto, A.1 aLee, Eleanor, S.1 aSelkowitz, Stephen, E.1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/simulating-energy-performance02087nas a2200181 4500008004100000024001100041245006100052210005700113260001200170520150200182100003401684700002501718700002101743700002101764700002701785700002301812856007001835 1993 eng d aDA-30200aThe Energy Performance of Prototype Holographic Glazings0 aEnergy Performance of Prototype Holographic Glazings c02/19933 a

We report on the simulation of the energy performance of prototype holographic glazings in commercial office buildings in a California climate. These prototype glazings, installed above conventional side windows, are designed to diffract the transmitted solar radiation and reflect it off the ceiling, providing adequate daylight illumination for typical office tasks up to 10m from the window. In this study, we experimentally determined a comprehensive set of solar-optical properties and characterized the contribution of the prototype holographic glazings to workplane illuminance in a scale model of a typical office space. We then used the scale model measurements to simulate the energy performance of the holographic glazings over the course of an entire year for four window orientations (North, East, South and West) for the inland Los Angeles climate, using the DOE-2.lD building energy analysis computer program. The results of our experimental analyses indicate that these prototype holographic glazings diffract only a small fraction of the incident light. The results of this study indicate that these prototype holographic glazings will not save energy in commercial office buildings. Their performance is very similar to that of clear glass, which, through side windows, cannot efficiently illuminate more than a 4m - 6m depth of a building`s perimeter, because the cooling penalties due to solar heat gain are greater than the electric lighting savings due to daylighting.

1 aPapamichael, Konstantinos, M.1 aBeltran, Liliana, O.1 aFurler, Reto, A.1 aLee, Eleanor, S.1 aSelkowitz, Stephen, E.1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/energy-performance-prototype02011nas a2200133 4500008004100000050001400041245011500055210006900170260002400239520148000263100003401743700002501777856007501802 1993 eng d aLBL-3394500aSimulating the Daylight Performance of Fenestration Systems and Spaces of Arbitrary Complexity: The IDC Method0 aSimulating the Daylight Performance of Fenestration Systems and  aAdelaide, Australia3 a

A new method to simulate the daylight performance of fenestration systems and spaces is presented. This new method, named IDC (Integration of Directional Coefficients), allows the simulation of the daylight performance of fenestration systems and spaces of arbitrary complexity, under any sun, sky and ground conditions. The IDC method is based on the combination of scale model photometry and computer-based simulation. Physical scale models are used to experimentally determine a comprehensive set of directional illuminance coefficients at reference points of interest, which are then used in analytical, computer-based routines, to determine daylight factors or actual daylight illuminance values under any sun, sky and ground conditions.

The main advantage of the IDC method is its applicability to any optically complex environment. Moreover, the computer-based analytical routines are fast enough to allow for hourly simulation of the daylight performance over the course of an entire year. However, the method requires appropriate experimental facilities for the determination of the Directional Coefficients. The IDC method has been implemented and used successfully in inter-validation procedures with various daylight simulation computer programs. Currently, it is used to simulate the daylight performance of fenestration systems that incorporate optically complex components, such as Venetian blinds, optically treated light shelves and light pipes.

1 aPapamichael, Konstantinos, M.1 aBeltran, Liliana, O. uhttps://facades.lbl.gov/publications/simulating-daylight-performance-002485nas a2200157 4500008004100000050001400041245007000055210006600125260002800191520191900219100003402138700002802172700002702200700002202227856007802249 1986 eng d aLBL-2053600aThe Integration of Operable Shading Systems and Lighting Controls0 aIntegration of Operable Shading Systems and Lighting Controls aLong Beach, CAc11/19863 a

Using daylighting in commercial buildings may significantly reduce electric lighting requirements if appropriatesphotoelectric controls are used to adjust the electric lighting output according to the available daylight. Prior analysis andsresults from monitored buildings and scale-model measurements suggest that the selection, placement, and installation ofsthe control photosensor is a difficult task, even with simple non-operable fenestration systems, since the daylightscontributions from sun, sky, and ground change continuously. The problem becomes even more complex forsfenestration systems that incorporate operable shading devices, because every adjustment changes the systems opticalsproperties. This paper presents results from measurements in a scale model under real skies, designed to bettersunderstand the problem of integrating fenestration and lighting controls. The scale model represented a typical officesspace and was equipped with motorized venetian blinds. Three control photosensors mounted on the ceiling weresconsidered for the operation of the electric lighting system, and two control strategies were considered for the operation ofsthe venetian blinds. Two ground-plane reflectances and two window orientations were examined. Results indicate thatsthe signal from a ceiling-mounted control photosensor shielded from direct light from the window shows the bestscorrelation with daylight work-plane illuminance, regardless of ground plane reflectance or venetian blind slat angle for allsslat angles that do not allow penetration of direct solar radiation. Results also indicate that the control strategies of thesvenetian blinds that were considered for the purposes of this study may result in significantly different slat angles, andsthus different daylighting work-plane illuminances and electric lighting requirements, especially when the ground-planesreflectance is high.

1 aPapamichael, Konstantinos, M.1 aRubinstein, Francis, M.1 aSelkowitz, Stephen, E.1 aWard, Gregory, J. uhttps://facades.lbl.gov/publications/integration-operable-shading-systems