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

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 kWh/m2 yr for commercial and 8–15 kWh/m2 yr for residential, in many regions on the order of 10%.

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-targets01241nas a2200181 4500008003900000022001400039245012000053210006900173260001200242300001100254490000700265520064300272100001900915700001900934700001800953700002000971856006800991 2012 d a0022-372700aThe ‘recycling trap’: a generalized explanation of discharge runaway in high-power impulse magnetron sputtering0 arecycling trap a generalized explanation of discharge runaway in c01/2012 a0120030 v453 a

Contrary to paradigm, magnetron discharge runaway cannot always be related to self-sputtering. We report here that the high density discharge can be observed with all conducting targets, including low sputter yield materials such as carbon. Runaway to a high density discharge is therefore generally based on self-sputtering in conjunction with the recycling of gas atoms in the magnetic field-affected pre-sheath. A generalized runaway condition can be formulated, offering a pathway to a time-dependent model for high-power impulse magnetron sputtering that includes rarefaction and an explanation for the termination of runaway.

1 aAnders, André1 aČapek, Jiří1 aHála, Matêj1 aMartinu, Ludvik uhttps://facades.lbl.gov/publications/recycling-trap-generalized01149nas a2200109 4500008004100000245009000041210006900131260001200200520074200212100001800954856006700972 2011 eng d00aRapid Prototyping Control Implementation using the Building Controls Virtual Test Bed0 aRapid Prototyping Control Implementation using the Building Cont c09/20113 a

This report documents the development of a rapid-prototyping control framework based on the Building Controls Virtual Test Bed co-simulation software. The objective of the developed framework is to establish the separation between the control algorithm and the physical systems such that the control algorithm can be rapidly revised and implemented without having to physically swap the controllers. The corresponding protocols and interfaces are designed for maximal flexibility, easy generalization and straightforward implementation. An instance of such control framework has been realized in the Advanced Windows Testing Facility at the Lawrence Berkeley National Laboratory and is used as a case study throughout this report.

1 aWen, Yao-Jung uhttps://facades.lbl.gov/publications/rapid-prototyping-control01869nas a2200157 4500008004100000245003300041210003200074260005100106520137600157100002001533700001901553700002501572700002201597700002301619856006901642 2005 eng d00aRESFEN5: Program Description0 aRESFEN5 Program Description bLawrence Berkeley National Laboratoryc05/20053 a

A computer tool such as RESFEN can help consumers and builders pick the most energy-efficient and cost-effective window for a given application, whether it is a new home, an addition, or a window replacement. It calculates heating and cooling energy use and associated costs as well as peak heating and cooling demand for specific window products. Users define a specific scenario by specifying house type (single-story or two-story), geographic location, orientation, electricity and gas cost, and building configuration details (such as wall, floor, and HVAC system type). Users also specify size, shading, and thermal properties of the window they wish to investigate. The thermal properties that RESFEN requires are: U-factor, Solar Heat Gain Coefficient, and air leakage rate. RESFEN calculates the energy and cost implications of the window compared to an insulated wall. The relative energy and cost impacts of two different windows can be compared.

RESFEN 3.0 was a major improvement over previous versions because it performs hourly calculations using a version of the DOE 2.1E (LBL 1980, Winkelmann et al. 1993) energy analysis simulation program. RESFEN 3.1 incorporates additional improvements including input assumptions for the base case buildings taken from the National Fenestration Rating Council (NFRC) Annual Energy Subcommittee's efforts.

1 aMitchell, Robin1 aHuang, Yu, Joe1 aArasteh, Dariush, K.1 aHuizenga, Charlie1 aGlendenning, Steve uhttps://facades.lbl.gov/publications/resfen5-program-description01366nas a2200169 4500008004100000022001500041245010600056210006900162260001200231300001200243490000700255520079100262100002301053700002301076700002101099856007601120 1999 eng d a0021-8979 00aRefractive Index Changes of Pd-Coated Magnesium Ianthanide Switchable Mirrors Upon Hydrogen Insertion0 aRefractive Index Changes of PdCoated Magnesium Ianthanide Switch c01/1999 a408-4130 v853 a

The optical effect upon insertion of hydrogen into Pd-coated magnesium lanthanide switchable mirrors is investigated in terms of the changes of their complex refractive indices. A significant change in the optical constants of LnMg layers is seen between the as-deposited state and the dehydrided state after one cycle. Furthermore, the optical effect of switching the Pd cap layer to a PdH cap layer was determined. It is shown that the Pd layer mainly limits the visible transmittance of the hydrided stack to about 35%-40%. Whereas the extinction coefficient of dehydrided LnMg layers at 550 nm is between 2.2 and 3.1, it is as low 10-4 as in the transparent state. This is of great promise to applications requiring large optical contrast (e.g., optical switches).

1 avon Rottkay, Klaus1 aRubin, Michael, D.1 aDuine, Peter, A. uhttps://facades.lbl.gov/publications/refractive-index-changes-pd-coated02024nas a2200169 4500008004100000024001100041245011600052210006900168260006100237520137600298100002001674700001901694700002501713700002101738700002101759856007401780 1999 eng d aBS-37100aRESFEN 3.1: A PC Program for Calculating the Heating and Cooling Energy Use of Windows in Residential Buildings0 aRESFEN 31 A PC Program for Calculating the Heating and Cooling E aBerkeleybLawrence Berkeley National Laboratoryc08/19993 a

A computer tool such as RESFEN can help consumers and builders pick the most energy-efficient and cost-effective window for a given application, whether it is a new home, an addition, or a window replacement. It calculates heating and cooling energy use and associated costs as well as peak heating and cooling demand for specific window products. Users define a specific scenario by specifying house type (single-story or two-story), geographic location, orientation, electricity and gas cost, and building configuration details (such as wall, floor, and HVAC system type). Users also specify size, shading, and thermal properties of the window they wish to investigate. The thermal properties that RESFEN requires are: U-factor, Solar Heat Gain Coefficient, and air leakage rate. RESFEN calculates the energy and cost implications of the window compared to an insulated wall. The relative energy and cost impacts of two different windows can be compared.

RESFEN 3.0 was a major improvement over previous versions because it performs hourly calculations using a version of the DOE 2.1E (LBL 1980, Winkelmann et al. 1993) energy analysis simulation program. RESFEN 3.1 incorporates additional improvements including input assumptions for the base case buildings taken from the National Fenestration Rating Council (NFRC) Annual Energy Subcommittee's efforts.

1 aMitchell, Robin1 aHuang, Yu, Joe1 aArasteh, Dariush, K.1 aSullivan, Robert1 aPhillip, Santosh uhttps://facades.lbl.gov/publications/resfen-31-pc-program-calculating02582nas a2200157 4500008004100000050001500041245006700056210006600123260003400189520203200223100001902255700002002274700002502294700002702319856007802346 1999 eng d aLBNL-4287100aResidential Fenestration Performance Analysis Using RESFEN 3.10 aResidential Fenestration Performance Analysis Using RESFEN 31 aClearwater Beach, FLc12/19983 a

This paper describes the development efforts of RESFEN 3.1, a PC-based computer program for calculating the heating and cooling energy performance and cost of residential fenestration systems. The development of RESFEN has been coordinated with ongoing efforts by the National Fenestration Rating Council (NFRC) to develop an energy rating system for windows and skylights to maintain maximum consistency between RESFEN and NFRCs planned energy rating system. Unlike previous versions of RESFEN, that used regression equations to replicate a large data base of computer simulations, Version 3.1 produces results based on actual hour-by-hour simulations. This approach has been facilitated by the exponential increase in the speed of personal computers in recent years. RESFEN 3.1 has the capability of analyzing the energy performance of windows in new residential buildings in 52 North American locations. The user describes the physical, thermal and optical properties of the windows in each orientation, solar heat gain reductions due to obstructions, overhangs, or shades, and the location of the house. The RESFEN program then models a prototypical house for that location and calculates the energy use of the house using the DOE-2 program. The user can vary the HVAC system, foundation type, and utility costs. Results are presented for the annual heating and cooling energy use, energy cost, and peak energy demand of the house, and the incremental energy use or peak demand attributable to the windows in each orientation. This paper describes the capabilities of RESFEN 3.1, its usefulness in analyzing the energy performance of residential windows and its development effort and gives insight into the structure of the computer program. It also discusses the rationale and benefits of the approach taken in RESFEN in combining a simple-to-use graphical front-end with a detailed hour-by-hour simulation engine to produce an energy analysis tool for the general public that is user-friendly yet highly accurate.

1 aHuang, Yu, Joe1 aMitchell, Robin1 aArasteh, Dariush, K.1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/residential-fenestration-performance01829nas a2200169 4500008004100000050001500041245008200056210006900138260003900207520123000246100002401476700002201500700001801522700001901540700002501559856007501584 1998 eng d aLBNL-4135200aRapid field testing of low-emittance coated glazings for product verification0 aRapid field testing of lowemittance coated glazings for product  aClearwater Beach, Floridac12/19983 a

This paper analyzes prospects for developing a test device suitable for field verification of the types of low-emittance (low-e) coatings present on high-performance window products. Test devices are currently available that can simply detect the presence of low-e coatings and that can measure other important characteristics of high-performance windows, such as the thickness of glazing layers or the gap in dual glazings. However, no devices have yet been developed that can measure gas concentrations or distinguish among types of coatings. This paper presents two optical methods for verification of low-e coatings. The first method uses a portable, fiber-optic spectrometer to characterize spectral reflectances from 650 to 1,100 nm for selected surfaces within an insulated glazing unit (IGU). The second method uses an infrared-light-emitting diode and a phototransistor to evaluate the aggregate normal reflectance of an IGU at 940 nm. Both methods measure reflectance in the near (solar) infrared spectrum and are useful for distinguishing between regular and spectrally selective low-e coatings. The infrared-diode/phototransistor method appears promising for use in a low-cost, hand-held field test device.

1 aGriffith, Brent, T.1 aKohler, Christian1 aGoudey, Howdy1 aTurler, Daniel1 aArasteh, Dariush, K. uhttps://facades.lbl.gov/publications/rapid-field-testing-low-emittance02619nas a2200169 4500008003900000024001100039245011600050210006900166260005100235300000700286520199700293100001902290700002102309700002502330700002002355856007402375 1997 d aBS-37100aRESFEN 3.0: A PC Program for Calculating the Heating and Cooling Energy Use of Windows in Residential Buildings0 aRESFEN 30 A PC Program for Calculating the Heating and Cooling E bLawrence Berkeley National Laboratoryc12/1997 a383 a

Today's energy-efficient windows can dramatically lower the heating and cooling costs associated with windows while increasing occupant comfort and minimizing window surface condensation problems. However, consumers are often confused about how to pick the most efficient window for their residence. They are typically given window properties such as U-factors or R-values, Solar Heat Gain Coefficients or Shading Coefficients, and air leakage rates. However, the relative importance of these properties depends on the site and building specific conditions. Furthermore, these properties are based on static evaluation conditions that are very different from the real situation the window will be used in. Knowing the energy and associated cost implications of different windows will help consumers and builders make the best decision for their particular application, whether it is a new home, an addition, or a window replacement.

A computer tool such as RESFEN can help consumers and builders pick the most energy-efficient and cost-effective window for a given application. It calculates the heating and cooling energy use and associated costs as well as the peak heating and cooling demand for specific window products. Users define a problem by specifying the house type (single story or two story), geographic location, orientation, electricity and gas cost, and building configuration details (such as wall type, floor type, and HVAC systems). Window options are defined by specifying the window`s size, shading, and thermal properties: U-factor, Solar Heat Gain Coefficient, and air leakage rate. RESFEN calculates the energy and cost implications of the windows compared to insulated walls. The relative energy and cost impacts of two different windows can be compared against each other.

RESFEN 3.0 is a major improvement over previous versions of RESFEN because it performs hourly calculations using a version of the DOE 2.1E energy analysis simulation program.

1 aHuang, Yu, Joe1 aSullivan, Robert1 aArasteh, Dariush, K.1 aMitchell, Robin uhttps://facades.lbl.gov/publications/resfen-30-pc-program-calculating01718nas a2200157 4500008004100000050001500041245006500056210006500121260002900186520117200215100002501387700002901412700002301441700001801464856007801482 1995 eng d aLBNL-4168000aRecent Technical Improvements to the WINDOW Computer Program0 aRecent Technical Improvements to the WINDOW Computer Program aToronto, Canadac06/19953 a

The WINDOW series of computer programs has been used since 1985 to model the thermal and optical properties of windows. Each succeeding version of WINDOW has brought its user base new technical capabilities, improvements to the user interface, and greater accuracy. Technical improvements to the current version, which will be released as version 5, are at first being released as stand-alone programs. This paper summarizes the capabilities and algorithms of two of these programs, THERM and LAMINATE. A third stand alone program, RESFEN, which calculates the annual energy effects of specific windows in a typical house throughout the US, will also be incorporated into WINDOW 5; because this program is already in use and documented, it is not discussed in this paper. THERM allows the user to evaluate two dimensional (2-D) heat transfer effects through the solid elements of a window while LAMINATE determines the optical properties of an individual glazing layer with an applied film. Both of these programs are undergoing final development at the time of this writing and will be released as separate programs before they are incorporated into WINDOW 5.

1 aArasteh, Dariush, K.1 aFinlayson, Elizabeth, U.1 aRubin, Michael, D.1 aSadlier, John uhttps://facades.lbl.gov/publications/recent-technical-improvements-window02457nas a2200145 4500008004100000050001400041245008800055210006900143260003400212520192400246100002102170700002302191700002702214856007002241 1995 eng d aLBL-3721100aReducing Residential Cooling Requirements Through the Use of Electrochromic Windows0 aReducing Residential Cooling Requirements Through the Use of Ele aClearwater Beach, FLc12/19953 a

This paper presents the results of a study investigating the energy performance of electrochromic windows in a prototypical residential building under a variety of state switching control strategies. We used the DOE-2.1E energy simulation program to analyze the annual cooling energy and peak demand as a function of glazing type, size, and electrochromic control strategy. A single-story ranch-style home located in the cooling-dominated locations of Miami, FL and Phoenix, AZ was simulated. Electrochromic control strategies analyzed were based on incident total solar radiation, space cooling load, and outside air temperature. Our results show that an electrochromic material with a high reflectance in the colored state provides the best performance for all control strategies. On the other hand, electrochromic switching using space cooling load provides the best performance for all the electrochrornic materials. The performance of the incident total solar radiation control strategy varies as a function of the values of solar radiation which trigger the bleached and colored states of the electrochromic (setpoint range); i.e., required cooling decreases as the setpoint range decreases; also, performance differences among electrochromics increases. The setpoint range of outside air temperature control of electrochromics must relate to the ambient weather conditions prevalent in a particular location. If the setpoint range is too large, electrochromic cooling performance is very poor. Electrochromics compare favorably to conventional low-E clear glazings that have high solar heat gain coefficients that are used with overhangs. However, low-E tinted glazings with low solar heat gain coefficients can outperform certain electrochromics. Overhangs should be considered as a design option for electrochromics whose state properties do not change significantly between bleached and colored states.

1 aSullivan, Robert1 aRubin, Michael, D.1 aSelkowitz, Stephen, E. uhttps://facades.lbl.gov/publications/reducing-residential-cooling01798nas a2200157 4500008004100000050001400041245005800055210005600113260003100169520127800200100002701478700002301505700002101528700002101549856007001570 1994 eng d aLBL-3548600aA Review of Electrochromic Window Performance Factors0 aReview of Electrochromic Window Performance Factors aFreiburg, Germanyc04/19943 a

The performance factors which will influence the market acceptance of electrochromic windows are reviewed. A set of data representing the optical properties of existing and foreseeable electrochromic window devices was generated. The issue of reflective versus absorbing electrochromics was explored. This data was used in the DOE 2.1 building energy model to calculate the expected energy savings compared to conventional glazings. The effects of several different control strategies were tested. Significant energy and peak electric demand benefits were obtained for some electrochromic types. Use of predictive control algorithms to optimize cooling control may result in greater energy savings. Initial economic results considering annual savings, cooling equipment cost savings, and electrochromic window costs are presented. Calculations of thermal and visual comfort show additional benefits from electrochromics but more work is needed to quantify their importance. The design freedom and aesthetic possibilities of these dynamic glazings should provide additional market benefits, but their impact is difficult to assess at this time. Ultimately, a full assessment of the market viability of electrochromics must consider the impacts of all of these issues.

1 aSelkowitz, Stephen, E.1 aRubin, Michael, D.1 aLee, Eleanor, S.1 aSullivan, Robert uhttps://facades.lbl.gov/publications/review-electrochromic-window