@article {57094, title = {Acceleration of the matrix multiplication of Radiance three phase daylighting simulations with parallel computing on heterogeneous hardware of personal computer}, journal = {Journal of Building Performance Simulation}, year = {2013}, abstract = {

Building designers are increasingly relying on complex fenestration systems to reduce energy consumed for lighting and HVAC in low energy buildings. Radiance, a lighting simulation program, has been used to conduct daylighting simulations for complex fenestration systems. Depending on the configurations, the simulation can take hours or even days using a personal computer. This paper describes how to accelerate the matrix multiplication portion of a Radiance three-phase daylight simulation by conducting parallel computing on heterogeneous hardware of a personal computer. The algorithm was optimized and the computational part was implemented in parallel using OpenCL. The speed of new approach was evaluated using various daylighting simulation cases on a multicore central processing unit and a graphics processing unit. Based on the measurements and analysis of the time usage for the Radiance daylighting simulation, further speedups can be achieved by using fast I/O devices and storing the data in a binary format.

}, keywords = {daylighting simulation, graphics processing unit, multicore central processing unit, OpenCL, parallel computing}, doi = {10.1080/19401493.2013.795193}, author = {Wangda Zuo and Andrew McNeil and Michael Wetter and Eleanor S. Lee} } @conference {57409, title = {Application of a stochastic window use model in EnergyPlus}, booktitle = {SimBuild 2012, 5th National Conference of IBPSA-USA, August 1-3, 2012}, year = {2012}, month = {08/2012}, address = {Madison, WI}, abstract = {

Natural ventilation, used appropriately, has the potential to provide both significant HVAC energy savings, and improvements in occupant satisfaction.

Central to the development of natural ventilation models is the need to accurately represent the behavior of building occupants. The work covered in this paper describes a method of implementing a stochastic window model in EnergyPlus. Simulated window use data from three stochastic window opening models was then compared to measured window opening behavior, collected in a naturally-ventilated office in California. Recommendations regarding the selection of stochastic window use models, and their implementation in EnergyPlus, are presented.

}, url = {https://escholarship.org/uc/item/2gm7r783}, author = {Spencer M. Dutton and Hui Zhang and Yongchao Zhai and Edward A. Arens and Youness Bennani Smires and Samuel L. Brunswick and Kyle S. Konis and Philip Haves} } @article {58917, title = {Improved structural and electrical properties of thin ZnO:Al films by dc filtered cathodic arc deposition}, journal = {Journal of Materials Research}, volume = {27}, year = {2012}, month = {3/2012}, pages = {857 - 862}, abstract = {

Transparent conducting oxide films are usually several 100-nm thick to achieve the required low sheet resistance. In this study, we show that the filtered cathodic arc technique produces high-quality low-cost ZnO:Al material for comparably smaller thicknesses than achieved by magnetron sputtering, making arc deposition a promising choice for applications requiring films less than 100-nm thick. A mean surface roughness less than 1 nm is observed for ZnO:Al films less than 100-nm thick, and 35-nm-thick ZnO:Al films exhibit Hall mobility of 28 cm2/Vs and a low resistivity of 6.5 {\texttimes} 10-4 Ωcm. Resistivity as low as 5.2 {\texttimes} 10-4 Ωcm and mobility as high as 43.5 cm2/Vs are obtained for 135-nm films.

}, keywords = {physical vapor deposition, Plasma deposition, Transparent conductor}, issn = {0884-2914}, doi = {10.1557/jmr.2011.342}, author = {Yuankun Zhu and Rueben J. Mendelsberg and Sunnie H.N. Lim and Jiaqi Zhu and Jiecai Han and Andr{\'e} Anders} } @techreport {3182, title = {Validation of the Window Model of the Modelica Buildings Library}, year = {2012}, month = {07/2012}, abstract = {

This paper describes the validation of the window model of the free open-source Modelica Buildings library. This paper starts by describing the physical modeling assumptions of the window model. The window model can be used to calculate the thermal and angular properties of glazing systems. It can also be used for steady-state simulation of heat transfer mechanism in glazing systems. We present simulation results obtained by comparing the window model with WINDOW 6 the well established simulation tool for steady-state heat transfer in glazing systems. We also present results obtained by comparing the window model with measurements carried out in a test cell at the Lawrence Berkeley National Laboratory.

}, author = {Thierry Stephane Nouidui and Michael Wetter and Wangda Zuo} } @conference {3385, title = {Acceleration of Radiance for Lighting Simulation by using Parallel Computing with OpenCL}, booktitle = {12th International Conference of the International Building Performance Simulation Association (Building Simulation 2011)}, year = {2011}, month = {11/2011}, pages = {p. 110-117}, address = {Sydney, Australia}, abstract = {

This study attempted to accelerate annual daylighting simulations for fenestration systems in Radiance ray-tracing program. The algorithm was optimized to reduce both the redundant data input/output operations and floating-point operations. To further accelerate the simulation speed, calculation for matrices multiplications was implemented in parallel on a graphics processing unit using OpenCL, a cross-platform parallel programming language. Numerical experiments show that combination of above measures can speed up the annual daylighting simulations 101.7 times or 28.6 times when sky vector has 146 or 2306 elements, respectively.

}, author = {Wangda Zuo and Andrew McNeil and Michael Wetter and Eleanor S. Lee} } @article {2974, title = {Achieving high mobility ZnO:Al at very high growth rates by dc filtered cathodic arc deposition}, journal = {Journal of Physics D: Applied Physics}, volume = {44}, year = {2011}, pages = {232003-232007}, chapter = {232003}, abstract = {

Achieving a high growth rate is paramount for making large-area transparent conducting oxide coatings at a low cost. Unfortunately, the quality of thin films grown by most techniques degrades as the growth rate increases. Filtered dc cathodic arc is a lesser known technique which produces a stream of highly ionized plasma, in stark contrast to the neutral atoms produced by standard sputter sources. Ions bring a large amount of potential energy to the growing surface which is in the form of heat, not momentum. By minimizing the distance from cathode to substrate, the high ion flux gives a very high effective growth temperature near the film surface without causing damage from bombardment. The high surface temperature is a direct consequence of the high growth rate and allows for high-quality crystal growth. Using this technique, 500{\textendash}1300\ nm thick and highly transparent ZnO\ :\ Al films were grown on glass at rates exceeding 250\ nm\ min-1 while maintaining resistivity below 5 {\texttimes} 10-4\ Ω\ cm with electron mobility as high as 60\ cm2\ V-1\ s-1.

}, doi = {10.1088/0022-3727/44/23/232003}, author = {Rueben J. Mendelsberg and Sunnie H.N. Lim and Yuankun Zhu and Joe Wallig and Delia J. Milliron and Andr{\'e} Anders} } @conference {11825, title = {Energy Efficient Windows in the Southern Residential Windows Market}, booktitle = {2002 ACEEE Summer Study on Energy Efficiency in Buildings}, year = {2002}, month = {08/2002}, address = {Pacific Grove, CA}, abstract = {

The greatest potential in the U.S. for cost-effective energy savings from currently available energy efficient residential windows and skylights exists in the southern market. Prindle and Arasteh recently reported that ten southern states could save over 400 million kwh and 233 MW of peak electricity generating capacity annually by adopting the International Energy Conservation Code (IECC) standard of 0.40 (or less) solar heat gain coefficient (SHGC) for new construction (Prindle \& Arasteh 2001). In 2000, Anello et al. demonstrated savings of 14.7 percent in reduced cooling load with high-performance windows (Anello et al. 2000). In 2002, Wilcox demonstrated savings of 20 percent while simulation analysis estimates cooling energy savings in the 30 percent range (Wilcox 2002).

In the southern market, there is significant opportunity for reducing cooling energy use with low solar gain low-E windows. Yet, the southern market has been slow to embrace this new technology. Market research shows that while low-E products have achieved up to 70 percent of the market share in some colder climates (Jennings, Degens \& Curtis 2002), they have gained less than 10 percent of the southern windows market (Prindle \& Arasteh 2001).

This paper will explore the residential windows market by considering the following: market barriers unique to the southern market; distribution channels in the South; the roles of utilities, codes officials, and other organizations; and other indirect factors that influence this market. This paper will profile current market transformation efforts with case studies of the Florida Windows Initiative, sponsored by the Efficient Windows Collaborative at the Alliance to Save Energy, and the Texas Windows Initiative, sponsored by the American Electric Power Company. Finally, this paper will identify the next steps that will be critical to transforming the southern residential windows market to more efficient window and skylight products.

}, author = {Alison Tribble and Kate Offringa and Bill Prindle and Dariush K. Arasteh and Jay Zarnikau and Arlene Stewart and Ken Nittler} } @techreport {1372, title = {Energy Performance Analysis of Electrochromic Windows in New York Commercial Office Buildings}, year = {2002}, month = {11/2002}, abstract = {

A DOE-2.1E energy simulation analysis of a switchable electrochromic (EC) glazing with daylighting controls has been conducted for prototypical office buildings in New York (NY). The modeling included four types of office buildings: "old" and "new" vintages and large (10,405 m2, 112,000 ft2) and small (502m2, 5400 ft2) buildings. Five commercially available, base case windows with and without interior shades were modeled. Window area varied from 0 to 60\% of the exterior floor-to-floor wall area. The electric lighting had either no controls or continuous daylighting controls. The prototypes were modeled in New York City or Buffalo.

Energy performance ata are given for each of the four perimeter zones. Data are presented as a function of window-to-wall ratio in order to better understand the interactions between 1) electric lighting energy use and daylight admission and 2) solar heat gains and space-conditioning energy use. Maximum and minimum reductions in energy use between the EC glazing and all other base case conditions are also presented. Projected energy use reductions relative to typical specified NY office buildings are presented as an indication of the potential impacts EC glazings might have in retrofit and new construction.

The energy and demand reductions provided by EC glazings with daylighting controls relative to what is typically specified in office buildings in NY are quite substantial. EC glazings will also dampen fluctuations in interior daylight levels and window brightness, potentially increasing visual comfort.

}, author = {Eleanor S. Lee and L. Zhou and Mehry Yazdanian and Vorapat Inkarojrit and Jonathan L. Slack and Michael D. Rubin and Stephen E. Selkowitz} }