@article {60938, title = {Balancing daylight, glare, and energy-efficiency goals: An evaluation of exterior coplanar shading systems using complex fenestration modeling tools}, journal = {Energy and Buildings}, volume = {112}, year = {2016}, month = {01/2016}, pages = {279-298}, abstract = {

Exterior shades are the most effective way to control solar load in buildings. Twelve different coplanar shades with different geometry, material properties and cut-off angles were investigated for two California climates: the moderate San Francisco Bay Area climate and a hot and dry Southern California climate. The presented results distinguish themselves from other simulation studies by a newly developed method that combines three research-grade software programs (Radiance, EnergyPlus and Window 7) to calculate heat transfer, daylight, and glare resulting from optically-complex fenestration systems more accurately. Simulations were run for a case with constant electric lighting and a case with daylighting controls for a prototypical, internal load dominated office building.

In the case of daylighting controls, the choice of slat angle and solar cut-off angle of a fixed exterior slat shading system is non trivial. An optimum slat angle was identified for the considered cases. Material properties (e.g., solar and visible reflectance) did not affect energy use if constant electric lighting was assumed, but they did have a significant influence on energy use intensity (EUI) when daylighting controls were assumed. Energy use increased substantially when an additional interior shade was used for glare control.

}, keywords = {Complex fenestration systems, Discomfort Glare, Energy Plus, Energy Use Intensity, Exterior shades, Glare Control, radiance}, doi = {10.1016/j.enbuild.2015.12.009}, author = {Sabine Hoffmann and Eleanor S. Lee and Andrew McNeil and Luis L. Fernandes and Dragan Vidanovic and Anothai Thanachareonkit} } @proceedings {60933, title = {Discomfort glare with complex fenestration systems and the impact on energy use when using daylighting control}, journal = {10th International Conference on Advanced Building Skins}, year = {2015}, month = {11/2015}, address = {Bern, Switzerland}, keywords = {building simulation, Complex fenestration systems, daylighting control, Discomfort Glare, Energy Use Intensity, radiance}, author = {Sabine Hoffmann and Andrew McNeil and Eleanor S. Lee and Raghuram Kalyanam} } @article {57807, title = {U.S. energy savings potential from dynamic daylighting control glazings}, journal = {Energy and Buildings}, volume = {66}, year = {2013}, month = {11/2013}, pages = {415-423}, chapter = {415}, abstract = {

Daylighting controls have the potential to reduce the substantial amount of electricity consumed for lighting in commercial buildings. Material science research is now pursuing the development of a dynamic prismatic optical element (dPOE) window coating that can continuously readjust incoming light to maximize the performance and energy savings available from daylighting controls. This study estimates the technical potential for energy savings available from vertical daylighting strategies and explores additional savings that may be available if current dPOE research culminates in a successful market-ready product. Radiance daylight simulations are conducted with a multi-shape prismatic window coating. Simulated lighting energy savings are then applied to perimeter floorspace estimates generated from U.S. commercial building stock data. Results indicate that fully functional dPOE coatings, when paired with conventional vertical daylight strategies, have the potential to reduce energy use associated with U.S. commercial electric lighting demand by as much as 930 TBtu. This reduction in electric lighting demand represents an approximately 85\% increase in the energy savings estimated from implementing conventional vertical daylight strategies alone. Results presented in this study provide insight into energy and cost performance targets for dPOE coatings, which can help accelerate the development process and establish a successful new daylighting technology.

}, keywords = {Clerestories, daylighting, Dynamic prismatic optical elements (dPOE), energy efficiency, Glare, indoor environmental quality, radiance, windows}, doi = {10.1016/j.enbuild.2013.07.013}, author = {Arman Shehabi and Nicholas DeForest and Andrew McNeil and Eric R. Masanet and Jeffery B. Greenblatt and Eleanor S. Lee and Georgeta Masson and Brett A. Helms and Delia J. Milliron} } @article {3184, title = {A validation of the Radiance three-phase simulation method for modeling annual daylight performance of optically-complex fenestration systems}, journal = {Journal of Building Performance Simulation}, volume = {April 2012}, year = {2012}, month = {05/2012}, keywords = {bidirectional scattering distribution functions, buildings energy efficiency, daylighting, radiance, validation}, doi = {10.1080/19401493.2012.671852}, author = {Andrew McNeil and Eleanor S. Lee} }