The primary goal of the judges' evaluation was to identify products that deliver both energy efficiency and lighting quality. The products featured are the best of the products submitted. They meet all the judging criteria and would be specified by most of the judges on the panel. The judges scored each entry on color, appropriate illuminance, light distribution, glare control, appearance, serviceability, value, and energy efficiency. Dimming was considered separately as a "bonus" item since not all entries were intended to dim.
Judges evaluated four separate criteria as part of lighting quality: color, illuminance, light distribution, and glare. The recognized products performed best in terms of color, illuminance, and light distribution – the highest performing criteria overall – and somewhat less well in terms of glare. Tellingly, color and distribution both showed the highest median results and lowest variation among all recognized products. Together with increasing efficacy (discussed below), highlights the substantial improvements manufacturers continue to make in product quality and performance.
The judges considered such attributes as composition, scale, proportion, and detailing, giving more consideration to those categories (such as decorative luminaires) where appearance is an important selection criterion.
Judges evaluated serviceability by inspecting the luminaires and attempting to access and replace the LED modules and drivers. Only four of the recognized luminaires had very good serviceability; 13 were considered no better than acceptable; and the median rating for all recognized products was the lowest of all the evaluation criteria.
NGL established minimum efficacy (lm/W) requirements for each category; entries that did not meet the minimum established values were not accepted. Entries were then evaluated on how their efficacy compared to the minimum for their category. Overall, the efficacy of the recognized luminaires improved significantly from previous years.
Manufacturers submitted reference pricing, which the judges evaluated in comparison to the performance, features, quality, and typical application of the products. Half of the recognized products were considered at least a good value. The balance did not impress the judges on this criterion. Readers should secure pricing for specific projects and applications from their market channels.
While LEDs are intrinsically dimmable, manufacturers of LED luminaires are still working to achieve satisfactory and predictable dimming performance. One reason is the difficulty of evaluating dimming on a consistent basis given different control systems, loads, power quality, and a host of other factors. NGL continues to grapple with this challenge.
For 2012, NGL entries were encouraged to submit a separate sample for dimming evaluation, supplying the dimmer of their choice. Judges considered lighting quality, as discussed above, based on non-dimmed, illuminated installed samples. Judges looked at dimming range, smoothness, and color consistency, among other parameters for the dimmable table-top products.
Twenty-one of the recognized luminaires dimmed at least reasonably well by the judges' evaluation; of these, nine dimmed very well. Their specific observations are reflected in their comments, but readers are urged to evaluate the dimmability of specific products considering the environment and application in which they will be used.