02791nas a2200289   4500008003900000022001300039245010400052210006900156260001200225300001400237490000700251520187700258653002002135653002802155653001802183653002402201653002002225100002302245700001902268700002202287700002802309700002202337700002102359700002702380700002402407856007002431       2013                          d  a0360132300aRegional performance targets for transparent near-infrared switching electrochromic window glazings0 aRegional performance targets for transparent nearinfrared switch  c03/2013  a160 - 1680 v613 a<p>With building heating and cooling accounting for nearly 14% of the national energy consumption, emerging technologies that improve building envelope performance have significant potential to reduce building energy consumption. Actual savings from these technologies will depend heavily upon their performance in diverse climate and operational conditions. In many cases, early-stage research can benefit from detailed investigation in order to develop performance thresholds and identify target markets. One example, a dynamic, highly transparent, near-infrared switching electrochromic (NEC) window glazing, is the focus of this investigation. Like conventional electrochromics, the NEC glazing can dynamically tune its optical properties with a small applied voltage. Consequently, the glazing can block or transmit solar heat to reduce cooling or heating loads, respectively. Unlike conventional electrochromics, NEC glazings remain transparent to visible light, causing no adverse effect to daylighting or building aesthetics. This study utilizes the software COMFEN to simulate a broad range of NEC performance levels, for commercial and residential buildings in 16 climate-representative reference cities. These simulations are the basis for identifying performance levels necessary to compete with existing static technologies. These results indicate that energy savings are strongly influenced by blocking-state performance. Additionally, residential applications have lower performance requirements due to their characteristic internal heat gains. Finally, the most dynamic NEC performance level is simulated in competition with high performing static alternatives. Here heating and cooling energy savings range from 5 to 11&nbsp;kWh/m<sup>2</sup> yr for commercial and 8–15&nbsp;kWh/m<sup>2</sup> yr for residential, in many regions on the order of 10%.</p>10aDynamic windows10aElectrochromic glazings10aNIR-switching10aPerformance targets10aSolar heat gain1 aDeForest, Nicholas1 aShehabi, Arman1 aGarcia, Guillermo1 aGreenblatt, Jeffery, B.1 aMasanet, Eric, R.1 aLee, Eleanor, S.1 aSelkowitz, Stephen, E.1 aMilliron, Delia, J.  uhttps://facades.lbl.gov/publications/regional-performance-targets02476nas a2200325   4500008003900000245007600039210006900115260001200184300001200196490000700208520149100215653001701706653001601723653004601739653002201785653001001807653003301817653001301850653001201863100001901875700002301894700001901917700002201936700002801958700002101986700002102007700002102028700002402049856007702073       2013                          d00aU.S. energy savings potential from dynamic daylighting control glazings0 aUS energy savings potential from dynamic daylighting control gla  c11/2013  a415-4230 v663 a<p>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.</p>10aClerestories10adaylighting10aDynamic prismatic optical elements (dPOE)10aenergy efficiency10aGlare10aindoor environmental quality10aradiance10awindows1 aShehabi, Arman1 aDeForest, Nicholas1 aMcNeil, Andrew1 aMasanet, Eric, R.1 aGreenblatt, Jeffery, B.1 aLee, Eleanor, S.1 aMasson, Georgeta1 aHelms, Brett, A.1 aMilliron, Delia, J.  uhttps://facades.lbl.gov/publications/us-energy-savings-potential-dynamic