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-targets