03133nas a2200205 4500008003900000245010300039210006900142260001200211300001200223490000700235520243300242653001602675653002302691653004002714653002602754653003202780100002002812700002102832856007402853 2015 d00aMeasured daylighting potential of a static optical louver system under real sun and sky conditions0 aMeasured daylighting potential of a static optical louver system c10/2015 a347-3590 v923 a
By utilizing highly specular surfaces and engineered profile geometry, optical sunlight redirecting systems integrated into the overhead “clerestory” zone of the building facade present the potential to enlarge the daylighting zone by redirecting the luminous flux incident on the window deeper into the space than conventional shading systems. In addition, by developing system geometry to redirect daylight to specific zones within the space, optical light redirecting systems have the potential to avoid the glare conditions commonly produced by conventional facade shading systems that direct significant amounts of daylight below head height into the occupant's field of view. In this case study, side-by-side comparisons were made over solstice-to-solstice changes in sun and sky conditions between an optical louver system (OLS) and a conventional Venetian blind set at a horizontal slat angle and located inboard of a south-facing, small-area, clerestory window in a full-scale office testbed. Daylight autonomy (DA), window luminance, and ceiling luminance uniformity were used to assess performance. The performance of both systems was found to have significant seasonal variation, where performance under clear sky conditions improved as maximum solar altitude angles transitioned from solstice to equinox. Although the OLS produced fewer hours per day of DA on average than the Venetian blind, the OLS never exceeded the designated 2000 cd/m2 threshold for window glare. In contrast, the Venetian blind was found to exceed the visual discomfort threshold over a large fraction of the day during equinox conditions (from 40 to 64% of the test day between August 22 and October 12). Notably, these peak periods of visual discomfort occurred during the best periods of daylighting performance. Luminance uniformity was analyzed using calibrated high dynamic range luminance images. Under clear sky conditions, the OLS was found to increase the luminance of the ceiling as well as produce a more uniform distribution of luminance over the ceiling. Compared to conventional venetian blinds, the static optical sunlight redirecting system studied has the potential to significantly reduce the annual electrical lighting energy demand of a daylit space and improve the quality from the perspective of building occupants by consistently transmitting useful daylight while eliminating window glare.
10adaylighting10afield measurements10ahigh dynamic range luminance images10aoptical louver system10asunlight redirecting system1 aKonis, Kyle, S.1 aLee, Eleanor, S. uhttps://facades.lbl.gov/publications/measured-daylighting-potential-002421nas a2200205 4500008003900000245011400039210006900153260001200222300001200234490000700246520171800253653003101971653001602002653002902018100002402047700002102071700002902092700001902121856007502140 2014 d00aMonitored lighting energy savings from dimmable lighting controls in The New York Times Headquarters Building0 aMonitored lighting energy savings from dimmable lighting control c01/2014 a498-5140 v683 aDigital addressable, dimmable lighting controls were introduced to the US market in the early 2000s with the promise of facilitating capture of potential energy savings with greater flexibility over their historic, typically unreliable, analog counterpart. The New York Times Company installed this emerging technology, after having tested the system thoroughly prior to procurement, in their new building in New York, New York. Four years after full occupancy in 2007, the owner agreed to participate in a post-occupancy monitored evaluation of the dimmable lighting system to verify actual performance in the field. Annual lighting energy savings from daylighting, setpoint tuning and occupancy controls were determined for the daylit, open-plan office areas on three typical floors (6, 11, and 20th floors) of the 51-story high-rise tower. Energy savings were calculated from ballast control signal and occupancy data recorded by the manufacturer's lighting control system. The ballast data were calibrated with independent measurements of lighting energy consumption. Savings from dimming controls (daylighting and setpoint tuning) were 12.6 kWh/m2-yr (1.17 kWh/ft2-yr) for the daylit spaces on the three floors overall, or 20%, relative to ASHRAE 90.1-2007. Compared to the prescriptive code in effect at the time of the building's construction (ASHRAE 90.1-2001), savings were 21.0 kWh/m2-yr (1.95 kWh/ft2-yr) or 28%. Annual lighting energy use with all lighting control strategies was 33.9 kWh/m2-yr (3.15 kWh/ft2-yr) in the daylit, open plan zones on average for the three floors. A simple payback analysis was conducted.
10aBuilding energy-efficiency10adaylighting10alighting control systems1 aFernandes, Luis, L.1 aLee, Eleanor, S.1 aDiBartolomeo, Dennis, L.1 aMcNeil, Andrew uhttps://facades.lbl.gov/publications/monitored-lighting-energy-savings01830nas a2200241 4500008003900000022001300039245013000052210006900182260001100251300001400262490000800276520103900284653002701323653003701350653002201387653001801409100002201427700002001449700001701469700001401486700001901500856006901519 2013 d a0927024800aModeling of optical and energy performance of tungsten-oxide-based electrochromic windows including their intermediate states0 aModeling of optical and energy performance of tungstenoxidebased c1/2013 a129 - 1350 v1083 aTungsten-oxide-based electrochromic (EC) windows are currently the most robust and matured dynamic windows where the transmittance of visual light and near-infrared radiation can be controlled by a small applied voltage. In its standard application, the window is commonly either in its clear or colored state. In this contribution, we study the optical and energy performance of such window in the fully bleached and fully colored state as well as when it is kept in intermediate states. Different configurations in terms of placement of the EC layer stack and possible additional low-emissivity (low-E) coating within the insulated glass unit are considered. Using optical data and software tools we find that even a small coloration has a significant effect on the energy performance because the solar heat gain coefficient is readily reduced by the absorption of the EC layer stack. We compare the performance of the EC windows to commercially available solar-control (spectrally selective) low-E windows.
10aElectrochromic windows10aEnergy efficient window modeling10aEnergy simulation10aSmart windows1 aLim, Sunnie, H.N.1 aIsidorsson, Jan1 aSun, Lizhong1 aKwak, Leo1 aAnders, André uhttps://facades.lbl.gov/publications/modeling-optical-and-energy01241nas a2200181 4500008003900000245009200039210006900131260001200200520059700212653002000809653002400829653003500853653002500888653003000913100002200943700002100965856007300986 2011 d00aModel-based controls for integrated shading and UFAD control: Report on initial studies0 aModelbased controls for integrated shading and UFAD control Repo c10/20113 aMethods and initial results are described for model-based controls with offline optimization for integrated shading and UFAD control for an office building in New York. Two cases are studied through lookup-table calculation and annual simulation of the resulting controllers: one case with interior blinds, the other case with exterior blinds. The interior blind case was found to reduce HVAC energy by 5% over a simple baseline control, and the exterior blind case produced a 5.6% HVAC energy savings over the baseline. Further investigations and case studies are planned.
The paper describes the development of a model specification for performance monitoring systems for commercial buildings. The specification focuses on four key aspects of performance monitoring:
The aim is to assist building owners in specifying the extensions to their control systems that are required to provide building operators with the information needed to operate their buildings more efficiently and to provide automated diagnostic tools with the information required to detect and diagnose faults and problems that degrade energy performance.
The paper reviews the potential benefits of performance monitoring, describes the specification guide and discusses briefly the ways in which it could be implemented. A prototype advanced visualization tool is also described, along with its application to performance monitoring. The paper concludes with a description of the ways in which the specification and the visualization tool are being disseminated and deployed.
1 aArasteh, Dariush, K.1 aKohler, Christian1 aGriffith, Brent, T. uhttps://facades.lbl.gov/publications/modeling-windows-energy-plus-simple01932nas a2200121 4500008004100000245009400041210006900135260002600204520146700230100002001697700001801717856007501735 2008 eng d00aA Modular Building Controls Virtual Test Bed for the Integration of Heterogeneous Systems0 aModular Building Controls Virtual Test Bed for the Integration o aBerkeley, CAc08/20083 aThis paper describes the Building Controls Virtual Test Bed (BCVTB) that is currently under development at Lawrence Berkeley National Laboratory. An earlier prototype linked EnergyPlus with controls hardware through embedded SPARK models and demonstrated its value in more cost-effective envelope design and improved controls sequences for the San Francisco Federal Building. The BCVTB presented here is a more modular design based on a middleware that we built using Ptolemy II, a modular software environment for design and analysis of heterogeneous systems. Ptolemy II provides a graphical model building environment, synchronizes the exchanged data and visualizes the system evolution during run-time. Our additions to Ptolemy II allow users to couple to Ptolemy II a prototype version of EnergyPlus, MATLAB/Simulink or other simulation programs for data exchange during run-time. In future work we will also implement a BACnet interface that allows coupling BACnet compliant building automation systems to Ptolemy II. We will present the architecture of the BCVTB and explain how users can add their own simulation programs to the BCVTB. We will then present an example application in which the building envelope and the HVAC system was simulated in EnergyPlus, the supervisory control logic was simulated in MATLAB/Simulink and Ptolemy II was used to exchange data during run-time and to provide real-time visualization as the simulation progresses.
1 aWetter, Michael1 aHaves, Philip uhttps://facades.lbl.gov/publications/modular-building-controls-virtual00634nas a2200109 4500008003900000245009300039210006900132260003200201520019600233100002200429856007300451 2007 d00aMoving from Niche to Mainstream Markets: Addressing the High Cost of Daylighting Systems0 aMoving from Niche to Mainstream Markets Addressing the High Cost aNew York, New Yorkc05/20073 aTranscript of a lecture given by Glenn Hughes, Managing Director of Construction, The New York Times at LightFair International: Daylighting Institute, New York, New York, May 6, 2007.
1 aHughes, Glenn, D. uhttps://facades.lbl.gov/publications/moving-niche-mainstream-markets01487nas a2200109 4500008004100000050001500041245005600056210005600112520112300168100001901291856006701310 2006 eng d aLBNL-6166500aMetal plasmas for the fabrication of nanostructures0 aMetal plasmas for the fabrication of nanostructures3 aA review is provided covering metal plasma production, the energetic condensation of metal plasmas, and the formation of nanostructures using such plasmas. Plasma production techniques include pulsed laser ablation, filtered cathodic arcs, and various forms of ionized physical vapor deposition, namely magnetron sputtering with ionization of sputtered atoms in radio frequency discharges, self-sputtering, and high power impulse magnetron sputtering. The discussion of energetic condensation focuses on the control of kinetic energy by biasing and also includes considerations of the potential energy and the processes occurring at subplantation and implantation. In the final section on nanostructures, two different approaches are discussed. In the top-down approach, the primary nanostructures are lithographically produced and metal plasma is used to coat or fill trenches and vias. Additionally, multilayers with nanosize periods (nanolaminates) can be produced. In the bottom-up approach, thermodynamic forces are used to fabricate nanocomposites and nanoporous materials by decomposition and dealloying.
1 aAnders, André uhttps://facades.lbl.gov/publications/metal-plasmas-fabrication02228nas a2200205 4500008004100000245010200041210006900143260003300212490001600245520148700261653003701748653002201785653002501807100002101832700002901853700002201882700002101904700002701925856007001952 2006 eng d00aMonitored Energy Performance of Electrochromic Windows Controlled for Daylight and Visual Comfort0 aMonitored Energy Performance of Electrochromic Windows Controlle aQuebec City, Canadac10/20060 v112 Issue 23 aA 20-month field study was conducted to measure the energy performance of south-facing large-area tungsten-oxide absorptive electrochromic (EC) windows with a broad switching range in a private office setting. The EC windows were controlled by a variety of means to bring in daylight while minimizing window glare. For some cases, a Venetian blind was coupled with the EC window to block direct sun. Some tests also involved dividing the EC window wall into zones where the upper EC zone was controlled to admit daylight while the lower zone was controlled to prevent glare yet permit view. If visual comfort requirements are addressed by EC control and Venetian blinds, a 2-zone EC window configuration provided average daily lighting energy savings of 10-15% compared to the reference case with fully lowered Venetian blinds. Cooling load reductions were 0-3%. If the reference case assumes no daylighting controls, lighting energy savings would be 44-11%. Peak demand reductions due to window cooling load, given a critical demand-response mode, were 19-26% maximum on clear sunny days. Peak demand reductions in lighting energy use were 0% or 72-100% compared to a reference case with and without daylighting controls, respectively. Lighting energy use was found to be very sensitive to how glare and sun is controlled. Additional research should be conducted to fine-tune EC control for visual comfort based on solar conditions so as to increase lighting energy savings.
10abuilding automation and controls10aBuilding envelope10acommercial buildings1 aLee, Eleanor, S.1 aDiBartolomeo, Dennis, L.1 aKlems, Joseph, H.1 aYazdanian, Mehry1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/monitored-energy-performance00500nas a2200109 4500008004100000245008400041210006900125260006000194300000800254100001700262856011100279 2005 eng d00aMaster of the House: Why a Company Should Take Control of Its Building Projects0 aMaster of the House Why a Company Should Take Control of Its Bui bHarvard Business School Publishing Corporationc10/2005 a1-81 aThurm, David uhttp://hbr.org/2005/10/master-of-the-house-why-a-company-should-take-control-of-its-building-projects/ar/102345nas a2200145 4500008004100000245010600041210006900147260003100216520178400247100002102031700002702052700002202079700002102101856007702122 2004 eng d00aMarket Transformation Opportunities for Emerging Dynamic Facade and Dimmable Lighting Control Systems0 aMarket Transformation Opportunities for Emerging Dynamic Facade aPacific Grove, CAc08/20043 aAutomated shading and daylighting control systems have been commercially available for decades. The new challenge is to provide a fully functional and integrated facade and lighting system that operates appropriately for all environmental conditions and meets a range of occupant subjective desires and objective performance requirements. These rigorous performance goals must be achieved with solutions that are cost effective and can operate over long periods with minimal maintenance. It will take time and effort to change the marketplace for these technologies and practices, particularly in building a series of documented success stories, and driving costs and risks to much lower levels at which their use becomes the norm. In recent years, the architectural trend toward highly-transparent all-glass buildings presents a unique challenge and opportunity to advance the market for emerging, smart, dynamic window and dimmable daylighting control technologies.
We believe it is possible to accelerate product market transformation by developing projects where technical advances and the interests of motivated manufacturers and innovative owners converge. In this paper we present a case study example that explains a building owners decision-making process to use dynamic window and dimmable daylighting controls. The case study project undertaken by a major building owner in partnership with a buildings R&D group was designed explicitly to use field test data in conjunction with the market influence of a major landmark building project in New York City to stimulate change in manufacturers product offerings. Preliminary observations on the performance of these systems are made. A cost model that was developed with the building owner is explained.
1 aLee, Eleanor, S.1 aSelkowitz, Stephen, E.1 aHughes, Glenn, D.1 aThurm, David, A. uhttps://facades.lbl.gov/publications/market-transformation-opportunities01325nas a2200109 4500008003900000245008200039210006900121260001200190520091800202100001901120856007601139 2002 d00aMaterials, processes, and issues in low-emissivity and solar control coatings0 aMaterials processes and issues in lowemissivity and solar contro c12/20023 aResearch at DOE and other laboratories can help addressing the durability, performance, and cost issues associated with the energy-saving coatings on glass used in windows of residential and commercial buildings. A brief review is presented on the status of energy-savings coatings, including material systems and processes to manufacture them. Issues such as durability, enhanced performance, dynamic coatings, and multifunctional coatings are considered. Industry and the Department of Energy have overlapping areas of interest, and therefore laboratories should and can have a role in energy-savings research and development of industrial relevance. The report includes specific recent results obtained at Berkeley Lab. It is argued that the properties of ultrathin silver films are determined both by the kinetics of the deposition process and the post-deposition thermodynamics of the material system.
1 aAnders, André uhttps://facades.lbl.gov/publications/materials-processes-and-issues-low01168nas a2200133 4500008004100000050001500041245004900056210004900105260002900154490001600183520073800199100002200937856007500959 2002 eng d aLBNL-5145300aMeasured Winter Performance of Storm Windows0 aMeasured Winter Performance of Storm Windows aKansas City, MOc07/20030 v109, Part 23 aDirect comparison measurements were made between various prime/storm window combinations and a well-weatherstripped, single-hung replacement window with a low-E selective glazing. Measurements were made using an accurate outdoor calorimetric facility with the windows facing north. The double-hung prime window was made intentionally leaky. Nevertheless, heat flows due to air infiltration were found to be small, and performance of the prime/storm combinations was approximately what would be expected from calculations that neglect air infiltration. Prime/low-E storm window combinations performed very similarly to the replacement window. Interestingly, solar heat gain was not negligible, even in north-facing orientation.
1 aKlems, Joseph, H. uhttps://facades.lbl.gov/publications/measured-winter-performance-storm01691nas 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 aThe 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-performance01381nas a2200169 4500008004100000245005700041210005700098260001200155300001400167490000700181520085100188100002701039700002401066700002001090700002301110856007801133 2001 eng d00aMixed Metal Films with Switchable Optical Properties0 aMixed Metal Films with Switchable Optical Properties c02/2002 a1349-13510 v803 aThin, Pd-capped metallic films containing magnesium and first row transition metals (Mn, Fe, Co) switch reversibly from their initial reflecting state to visually transparent states when exposed to gaseous hydrogen or following reduction cathodic polarization in an alkaline electrolyte. Reversion to the reflecting state is achieved by exposure to air or by anodic polarization. The films were prepared by co-sputtering from one magnesium target and one manganese, iron, or cobalt target. Both the dynamic optical switching range and the speed of the transition depend on the magnesium-transition metal ratio. Infrared spectra of films in the transparent, hydrided (deuterided) states support the presence of the intermetallic hydride phases Mg3MnH7, Mg2FeH6, and Mg2CoH5.
1 aRichardson, Thomas, J.1 aSlack, Jonathan, L.1 aFarangis, Baker1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/mixed-metal-films-switchable-optical00835nas a2200145 4500008004100000050001400041245004700055210004700102260003400149520037100183100002200554700002100576700002000597856007200617 1995 eng d aLBL-3774700aMeasured Performance of Selective Glazings0 aMeasured Performance of Selective Glazings aClearwater Beach, FLc12/19953 aMeasurements of the net heat flow through four selective glazings in comparison with clear double glazing under late summer outdoor conditions are presented. The solar heat gain coefficient (SHGC) for each glazing is extracted from the data and shown to be angle-dependent. Good agreement is found between measured properties and calculations with WINDOW 4.1.
1 aKlems, Joseph, H.1 aYazdanian, Mehry1 aKelley, Guy, O. uhttps://facades.lbl.gov/publications/measured-performance-selective01775nas a2200133 4500008004100000050001400041245007900055210006900134490001600203520130100219100002201520700002401542856007501566 1995 eng d aLBL-3624300aMeasurement of Bidirectional Optical Properties of Complex Shading Devices0 aMeasurement of Bidirectional Optical Properties of Complex Shadi0 v101, Part 13 aA new method of predicting the solar heat gain through complex fenestration systems involving nonspecular layers such as shades or blinds has been examined in a project jointly sponsored by ASHRAE and DOE. In this method, a scanning radiometer is used to measure the bidirectional radiative transmittance and reflectance of each layer of a fenestration system. The properties of systems containing these layers are then built up computationally from the measured layer properties using a transmission/multiple-reflection calculation. The calculation produces the total directional-hemispherical transmittance of the fenestration system and the layer-by-layer absorptances. These properties are in turn combined with layer-specific measurements of the inward-flowing fractions of absorbed solar energy to produce the overall solar heat gain coefficient.
This paper describes the method of measuring the spatially averaged bidirectional optical properties using an automated, large-sample gonio-radiometer/photometer, termed a Scanning Radiometer. Property measurements are presented for one of the most optically complex systems in common use, a venetian blind. These measurements will form the basis for optical system calculations used to test the method of determining performance.
1 aKlems, Joseph, H.1 aWarner, Jeffrey, L. uhttps://facades.lbl.gov/publications/measurement-bidirectional-optical01532nas a2200157 4500008004100000050001400041245003300055210003200088260003400120520105600154100001801210700003001228700002501258700002501283856006601308 1994 eng d aLBL-3319200aModeling Windows in DOE 2.1E0 aModeling Windows in DOE 21E aClearwater Beach, FLc12/19923 aThe most recent version of the DOE-2 building energy simulation program, DOE-2.1E, provides for more detailed modeling of the thermal and optical properties of windows. The window calculations account for the temperature effects on U-value, and update the incident angle correlations for the solar heat gain properties and visible transmittance. Initial studies show up to a 30% difference in calculating peak solar heat gain between the detailed approach and a constant shading-coefficient approach. The modeling approach is adapted from Lawrence Berkeley Laboratorys WINDOW 4 computer program, which is used in the National Fenestration Rating Council (NFRC) U-value rating procedure 100-91. This gives DOE-2.1E the capability to assess the annual and peak energy performance of windows consistent with the NFRC procedure. The program has an extensive window library and algorithms for simulating switchable glazings. The program also accounts for the influence of framing elements on the heat transfer and solar heat gain through the window.
1 aReilly, Susan1 aWinkelmann, Frederick, C.1 aArasteh, Dariush, K.1 aCarroll, William, L. uhttps://facades.lbl.gov/publications/modeling-windows-doe-21e01301nas a2200133 4500008004100000050001400041245009400055210006900149490001600218520081200234100002101046700002201067856007801089 1993 eng d aLBL-3471700aMeasurement of the Exterior Convective Film Coefficient for Windows in Low-Rise Buildings0 aMeasurement of the Exterior Convective Film Coefficient for Wind0 v100, Part 13 aThe MoWiTT field facility is used to measure the convective film coefficient over the exterior surface of a window. The MoWiTT-measured data is compared to some commonly-used experimental and theoretical models. The comparison shows that the MoWiTT data disagrees with the previously used models such as the ASHRAE/DOE-2 model. The reasons for these disagreements are discussed. An experimental model, based on the MoWiTT data, is presented to correlate the film coefficient with the difference in temperatures of the exterior glass surface and the ambient, in the natural convection region, and with the site wind speed, in the forced convection region. The wind speed is considered both in windward and leeward hemispheres. The validity of the MoWiTT model for low-rise buildings is then discussed.
1 aYazdanian, Mehry1 aKlems, Joseph, H. uhttps://facades.lbl.gov/publications/measurement-exterior-convective-film