@article {60093, title = {Measured daylighting potential of a static optical louver system under real sun and sky conditions}, journal = {Building and Environment}, volume = {92}, year = {2015}, month = {10/2015}, pages = {347-359}, chapter = {347}, abstract = {

By utilizing highly specular surfaces and engineered profile geometry, optical sunlight redirecting systems integrated into the overhead {\textquotedblleft}clerestory{\textquotedblright} 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{\textquoteright}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.

}, keywords = {daylighting, field measurements, high dynamic range luminance images, optical louver system, sunlight redirecting system}, doi = {10.1016/j.buildenv.2015.04.024}, author = {Kyle S. Konis and Eleanor S. Lee} } @article {55580, title = {Monitored lighting energy savings from dimmable lighting controls in The New York Times Headquarters Building}, journal = {Energy and Buildings}, volume = {68}, year = {2014}, month = {01/2014}, pages = {498-514}, chapter = {498}, abstract = {

Digital 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{\textquoteright}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{\textquoteright}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.

}, keywords = {Building energy-efficiency, daylighting, lighting control systems}, doi = {10.1016/j.enbuild.2013.10.009}, author = {Luis L. Fernandes and Eleanor S. Lee and Dennis L. DiBartolomeo and Andrew McNeil} } @article {58920, title = {Modeling of optical and energy performance of tungsten-oxide-based electrochromic windows including their intermediate states}, journal = {Solar Energy Materials and Solar Cells}, volume = {108}, year = {2013}, month = {1/2013}, pages = {129 - 135}, abstract = {

Tungsten-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.

}, keywords = {Electrochromic windows, Energy efficient window modeling, Energy simulation, Smart windows}, issn = {09270248}, doi = {10.1016/j.solmat.2012.09.010}, author = {Sunnie H.N. Lim and Jan Isidorsson and Lizhong Sun and B. Leo Kwak and Andr{\'e} Anders} } @techreport {58299, title = {Model-based controls for integrated shading and UFAD control: Report on initial studies}, year = {2011}, month = {10/2011}, type = {DOE/ CEC PIER Technical Report}, abstract = {

Methods 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.

}, keywords = {cloud computing, integrated controls, Model predictive control (MPC), offline optimization, shading and HVAC controls}, author = {Brian E. Coffey and Eleanor S. Lee} } @techreport {58281, title = {Modeling solar heat gains of complex fenestration systems using bidirectional scattering distribution functions}, year = {2011}, month = {09/2011}, type = {DOE/ CEC PIER Technical Report}, author = {Thierry Stephane Nouidui and Andrew McNeil and Christian Kohler and Brian E. Coffey and Eleanor S. Lee} } @techreport {1631, title = {Modeling Windows in Energy Plus with Simple Performance Indices}, year = {2009}, month = {10/2009}, abstract = {

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.

}, author = {Dariush K. Arasteh and Christian Kohler and Brent T. Griffith} } @conference {61, title = {A Modular Building Controls Virtual Test Bed for the Integration of Heterogeneous Systems}, booktitle = {SimBuild 2008, July 30-August 1}, year = {2008}, month = {08/2008}, address = {Berkeley, CA}, abstract = {

This 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.

}, author = {Michael Wetter and Philip Haves} } @techreport {58255, title = {Moving from Niche to Mainstream Markets: Addressing the High Cost of Daylighting Systems}, year = {2007}, month = {05/2007}, address = {New York, New York}, abstract = {

Transcript 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.

}, author = {Glenn D. Hughes} } @article {12067, title = {Metal plasmas for the fabrication of nanostructures}, journal = {J. Phys. D: Appl. Phys.}, year = {2006}, abstract = {

A 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.

}, author = {Andr{\'e} Anders} } @conference {12088, title = {Monitored Energy Performance of Electrochromic Windows Controlled for Daylight and Visual Comfort}, booktitle = {2006 ASHRAE Annual Meeting}, volume = {112 Issue 2}, year = {2006}, month = {10/2006}, address = {Quebec City, Canada}, abstract = {

A 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.

}, keywords = {building automation and controls, Building envelope, commercial buildings}, author = {Eleanor S. Lee and Dennis L. DiBartolomeo and Joseph H. Klems and Mehry Yazdanian and Stephen E. Selkowitz} } @article {1222, title = {Master of the House: Why a Company Should Take Control of Its Building Projects}, journal = {Harvard Business Review}, year = {2005}, month = {10/2005}, pages = {1-8}, publisher = {Harvard Business School Publishing Corporation}, url = {http://hbr.org/2005/10/master-of-the-house-why-a-company-should-take-control-of-its-building-projects/ar/1}, author = {David Thurm} } @conference {12049, title = {Market Transformation Opportunities for Emerging Dynamic Facade and Dimmable Lighting Control Systems}, booktitle = {2004 ACEEE Summer Study on Energy Efficiency in Buildings}, year = {2004}, month = {08/2004}, address = {Pacific Grove, CA}, abstract = {

Automated 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.

}, author = {Eleanor S. Lee and Stephen E. Selkowitz and Glenn D. Hughes and David A. Thurm} } @techreport {58287, title = {Materials, processes, and issues in low-emissivity and solar control coatings}, year = {2002}, month = {12/2002}, abstract = {

Research 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.

}, author = {Andr{\'e} Anders} } @article {12056, title = {Measured Winter Performance of Storm Windows}, journal = {ASHRAE Transactions}, volume = {109, Part 2}, year = {2002}, month = {07/2003}, address = {Kansas City, MO}, abstract = {

Direct 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.

}, author = {Joseph H. Klems} } @article {12068, title = {A Method for Simulating the Performance of Photosensor-Based Lighting Controls}, journal = {Energy and Buildings}, volume = {34}, number = {9}, year = {2001}, pages = {883-889}, abstract = {

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.

}, author = {Charles K. Ehrlich and Konstantinos M. Papamichael and Judy Lai and Kenneth L. Revzan} } @article {12075, title = {Mixed Metal Films with Switchable Optical Properties}, journal = {Applied Physics Letters}, volume = {80}, number = {8}, year = {2001}, month = {02/2002}, pages = {1349-1351}, abstract = {

Thin, 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.

}, doi = {10.1063/1.1454218}, author = {Thomas J. Richardson and Jonathan L. Slack and Baker Farangis and Michael D. Rubin} } @conference {12055, title = {Measured Performance of Selective Glazings}, booktitle = {Thermal Performance of the Exterior Envelopes of Buildings VI Conference }, year = {1995}, month = {12/1995}, address = {Clearwater Beach, FL}, abstract = {

Measurements 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.

}, author = {Joseph H. Klems and Mehry Yazdanian and Guy O. Kelley} } @article {12058, title = {Measurement of Bidirectional Optical Properties of Complex Shading Devices}, journal = {ASHRAE Transactions}, volume = {101, Part 1}, year = {1995}, abstract = {

A 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.

}, author = {Joseph H. Klems and Jeffrey L. Warner} } @conference {12084, title = {Modeling Windows in DOE 2.1E}, booktitle = {Thermal Performance of the Exterior Envelopes of Buildings V Conference}, year = {1994}, month = {12/1992}, address = {Clearwater Beach, FL}, abstract = {

The 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.

}, author = {M. Susan Reilly and Frederick C. Winkelmann and Dariush K. Arasteh and William L. Carroll} } @article {12065, title = {Measurement of the Exterior Convective Film Coefficient for Windows in Low-Rise Buildings}, journal = {ASHRAE Transactions}, volume = {100, Part 1}, year = {1993}, abstract = {

The 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.

}, author = {Mehry Yazdanian and Joseph H. Klems} }