02267nas a2200229 4500008004100000245011200041210006900153260001200222300001200234490000700246520149000253653003501743653004001778653001601818653002301834653002701857100002201884700001801906700002001924700002101944856007201965 2011 eng d00aPerformance of Integrated Systems of Automated Roller Shade Systems and Daylight Responsive Dimming Systems0 aPerformance of Integrated Systems of Automated Roller Shade Syst c03/2011 a747-7570 v463 a

Daylight responsive dimming systems have been used in few buildings to date because they require improvements to improve reliability. The key underlying factor contributing to poor performance is the variability of the ratio of the photosensor signal to daylight workplane illuminance in accordance with sun position, sky condition, and fenestration condition. Therefore, this paper describes the integrated systems between automated roller shade systems and daylight responsive dimming systems with an improved closed-loop proportional control algorithm, and the relative performance of the integrated systems and single systems. The concept of the improved closed-loop proportional control algorithm for the integrated systems is to predict the varying correlation of photosensor signal to daylight workplane illuminance according to roller shade height and sky conditions for improvement of the system accuracy. In this study, the performance of the integrated systems with two improved closed-loop proportional control algorithms was compared with that of the current (modified) closed-loop proportional control algorithm. In the results, the average maintenance percentage and the average discrepancies of the target illuminance, as well as the average time under 90% of target illuminance for the integrated systems significantly improved in comparison with the current closed-loop proportional control algorithm for daylight responsive dimming systems as a single system.

10aautomated roller shade systems10adaylight responsive dimming systems10adaylighting10aIntegrated systems10aphotoelectric controls1 aPark, Byoung-Chul1 aChoi, An-Seop1 aJeong, Jae-Weon1 aLee, Eleanor, S. uhttps://facades.lbl.gov/publications/performance-integrated-systems02555nas a2200205 4500008003900000245009100039210006900130260001200199300001200211490000800223520188300231100002102114700002902135700002202164700002202186700002002208700002102228700002202249856007802271 2009 d00aField Measurements of Innovative Indoor Shading Systems in a Full-Scale Office Testbed0 aField Measurements of Innovative Indoor Shading Systems in a Ful c10/2009 a706-7280 v1153 a

The development of spectrally selective low-e glass with its superior solar control and high daylight admission has led to widespread use of large-area, "transparent" or visually clear glass windows in commercial building facades. This type of façade can provide significant inherent daylighting potential (ability to offset lighting energy use) and move us closer to the goal of achieving zero energy buildings, if not for the unmitigated glare that results from the unshaded glazing. Conventional shading systems result in a significant loss of daylight and view. Can innovative shading solutions successfully balance the tradeoffs between daylight, solar heat gains, discomfort glare, and view?

To investigate this issue, a six-month solstice-to-solstice field study was conducted in a sunny climate to measure the thermal and daylighting performance of a south-facing, full- scale, office testbed with large-area windows and a variety of innovative indoor shading systems. Indoor shading systems included manually-operated and automated roller shades, Venetian blinds, daylight-redirecting blinds, and a static translucent diffusing panel placed inboard of the window glazing. These innovative systems were compared to a reference shade lowered to block direct sun.

With continuous dimming controls, all shading systems yielded lighting energy savings between 43-69% compared to a non-dimming case, but only the automated systems were able to meet visual comfort criteria throughout the entire monitored period. Cooling loads due to solar and thermal loads from the window were increased by 2-10% while peak cooling loads were decreased by up to 14%. The results from this experiment illustrate that some indoor shading systems can preserve daylight potential while meeting comfort requirements. Trends will differ significantly depending on application.

1 aLee, Eleanor, S.1 aDiBartolomeo, Dennis, L.1 aKlems, Joseph, H.1 aClear, Robert, D.1 aKonis, Kyle, S.1 aYazdanian, Mehry1 aPark, Byoung-Chul uhttps://facades.lbl.gov/publications/field-measurements-innovative-indoor