%0 Report %D 2014 %T High Performance Building Façade Solutions-Phase II %A Eleanor S. Lee %A Brian E. Coffey %A Luis L. Fernandes %A Sabine Hoffmann %A Andrew McNeil %A Anothai Thanachareonkit %A Gregory J. Ward %K automated shading %K between-pane shading %K bidirectional scattering distribution functions %K building energy simulation tools %K Complex fenestration systems %K daylighting %K daylighting simulation tools %K electrochromics %K exterior shading %K goniophotometer %K light shelves %K microprismatic films %K model predictive controls %K motorized shading %K shading %K solar-optical properties %K switchable windows %K thermochromics %K virtual prototyping %K window heat transfer %X

The High Performance Building Façade Solutions–Phase II project was initiated through the California Energy Commission’s Public Interest Energy Research (PIER) program in July 2010 to support industry’s development and deployment of both incremental and breakthrough façade technologies in partnership with the U.S. Department of Energy (DOE). The objective of this three-year project was to develop, or support the development and deployment of, promising near-term and emerging zero net energy building façade technologies for solar control and daylighting, addressing two of the largest end uses in California commercial buildings: cooling and lighting. In partnership with industry (such as manufacturers), three classes of technologies were investigated: daylighting systems, angular-selective shading systems, and dynamic façade systems. Commercially available and emerging prototype technologies were developed and evaluated using laboratory tests. Simulations, full-scale outdoor tests in the Advanced Window Testbed, and demonstration projects quantified energy and peak electric demand reductions and occupant satisfaction, acceptance, and comfort associated with the resultant indoor environment. Several new technologies were developed using virtual prototyping tools. Integrated control systems were developed using model predictive controls. Simulation tools were developed to model operable complex fenestration systems such as shades and microprismatic films. A schematic design tool called COMFEN was developed to facilitate evaluation of these advanced technologies in the early design phase. All three classes of technologies resulted in significant reductions in perimeter zone energy use and peak electric demand, providing viable options that can support California’s long-term goal of achieving zero net energy use in the next decade.

%8 03/2014 %2 LBNL-1004337 %0 Report %D 2013 %T Annual daylighting performance of a passive optical light shelf in sidelit perimeter zones of commercial buildings %A Andrew McNeil %A Eleanor S. Lee %K bidirectional scattering distribution functions %K buildings energy efficiency %K daylighting %K Radiance simulations %X

Sunlight redirecting systems have the potential to significantly offset electric lighting energy use in deep perimeter zones of buildings where the windows are subject to high daylight availability. New Radiance modeling tools have recently been developed and validated, enabling accurate and timely simulation analysis of the annual energy and comfort performance of these optically-complex, anisotropic systems. A parametric study was conducted using these tools to evaluate the performance of a commercially-available passive optical light shelf (OLS) in a 17.4 m deep (57 ft), south-facing open plan office zone in three climates. Daylighting efficiency, discomfort glare, and lighting energy savings with continuous dimming and bi-level switching controls were determined at varying depths within the zone. The OLS decreased lighting energy use significantly throughout the depth of the space and achieved these savings with minimal discomfort glare in the area near the window. Annual lighting energy use intensity was reduced to 1.71-1.82 kWh/ft2-yr (22-27%) over the full depth of the perimeter zone across the three climates modeled (Phoenix, Washington DC, and Minneapolis) compared to a non-daylit zone at 2.34 kWh/ft2-yr. There was a greater occurrence of discomfort glare (3-7% during daytime work hours) if the occupant was in a seated view position looking at the window from the back of the room. The system is passive, needing no adjustment during the day and over the seasons and can be used as a retrofit measure in existing buildings. These results are encouraging and demonstrate how the primary daylit sidelit area can be extended well beyond the defined limits provided by the newly adopted ASHRAE 90.1-2010 code (i.e., 1.0 times the head height of the window).

%0 Journal Article %J Journal of Building Performance Simulation %D 2012 %T A validation of the Radiance three-phase simulation method for modeling annual daylight performance of optically-complex fenestration systems %A Andrew McNeil %A Eleanor S. Lee %K bidirectional scattering distribution functions %K buildings energy efficiency %K daylighting %K radiance %K validation %B Journal of Building Performance Simulation %V April 2012 %8 05/2012 %2 LBNL-5606E %R 10.1080/19401493.2012.671852