The Journal of the Illuminating Engineering Society of North America: Volume 8 | Number 3 | January 2012

Publisher's data

Public Policy, Lighting Quality, and the Incandescent Lamp

LIGHTING CONTROLS IN COMMERCIAL BUILDINGS

ALISON WILLIAMS, BARBARA ATKINSON, KARINA GARBESI, ERIK PAGE, AND FRANCIS RUBINSTEIN

This study provides a meta-analysis of energy savings identified in the literature—240 savings estimates from 88 papers and case studies, categorized into daylighting strategies, occupancy strategies, personal tuning, and institutional tuning. Beginning with an overall average of savings estimates by control strategy, successive analytical filters are added to identify potential biases introduced to the estimates by different analytical approaches. Based on the meta-analysis, the best estimates of average energy savings potential are 24 percent for occupancy, 28 percent for daylighting, 31 percent for personal tuning, 36 percent for institutional tuning, and 38 percent for multiple approaches. The results suggest that simulations overestimate by at least 10 percent the average savings obtainable from daylighting in actual buildings.

COMPARISON OF THE VIGNETTING EFFECTS OF TWO IDENTICAL FISHEYE LENSES

CORALIE CAUWERTS, MAGALI BODART, AND ARNAUD DENEYER

High dynamic range (HDR) imaging techniques are increasingly used by lighting researchers in building applications to capture luminances in the field of view. This paper deals with the photometric calibration and more particularly with vignetting effect correction, which is one of the steps necessary to ensure reliable data. The vignetting effects of four similar devices (two identical fisheye lenses successively mounted on two identical cameras) were first determined for several apertures. The symmetry, noninfluence of the color of the target, and the similarity of vignetting between the devices were evaluated with root mean square error. We conclude that the vignetting filters determined for one device (a SIGMA 4.5 mm F2.8 fisheye lens mounted on a CANON 40D camera) can be reasonably used by other researchers using the same brands and models of photographic equipment.

COMPARATIVE IN SITU STUDY OF LEDS AND HPS IN ROAD LIGHTING

FUSHENG LI, YUMING CHEN, YANG LIU, AND DAHUA CHEN

The effect of spectrum on the visibility of roadway lighting targets was investigated. The experiment focused on the relationship between average visibility ratings and small target visibility (STV) under installations that employed LED and HPS light sources. Achromatic targets were more visible under LEDs illumination conditions than under HPS illumination conditions. The results also suggest that the visibility of colored objects on the road was better under LEDs illumination conditions in comparison to HPS. The results cannot be generalized to all LED light sources, but are likely indicative of LEDs with similar spectral power distributions (SPDs). Relative visibility under source types with different SPDs, and which provide different luminance distributions, should merit consideration when selecting a light source for roadway lighting.

DESIGNING TANGIBLE LIGHTING CONTROL INTERFACES

AMARDEEP M. DUGAR, MICHAEL R. DONN, AND STUART MARSHALL

This paper aims to design a prototype tangible user interface (TUI) for lighting control and test its usability and end-user experience against a prototype conventional interface. Usability is concerned with easier understanding of control functions. End-user experience is concerned with explicating the quality of end-users’ experience such as fun and pleasure of use. TUIs that offer end-users freedom of personal expression alongside functional information are proposed as a basis for making lighting control systems easier to understand and more pleasurable to use. Three dominant views on tangible interaction are explored to derive a set of synthesized principles for designing tangible lighting control interfaces. These principles—which determine what end-users should see and do while using lighting control interfaces and provide specific guidelines for enhancing their physical interaction possibilities—are used to design a prototype tangible interface. Several tests were performed to obtain end-user responses towards the usability and end-user experience of the tangible interface as well as a conventional interface. End-user responses obtained from these tests challenge manufacturers’ claims about the effectiveness of conventional lighting control interfaces and reveal a different way of thinking about future interface designs. Such a change in thinking could lead to lighting control interface designs that are easier to understand and more pleasurable to use.