Metal halide fixtures created problems because of color appearance, color rendering,
and ballast and transformer noise.
Insufficient daylighting control (less than optimal window shades).
Task areas were often not treated differently than non-task (e.g., audience) areas,
resulting in higher power density than is necessary.
2.4.2. Synthesis of Findings from GSA Staff Interviews
Insufficient light at the walls (luminance), largely resulting from the use of dark
finishes, primarily wood walls.
Insufficient vertical illuminance, resulting in complaints from judges about facial
modeling and evidence display.
Spaces are perceived as underlit because of the low room surface brightness. This has
required expensive relighting projects subsequent to initial construction, which usually
increases power density.
Control systems that are not user-friendly.
There have been problems with ceiling plane and room geometries, where the lighting
design did not respond to the architectural requirements of the space.
Glare from lighting fixtures and occasionally windows as well.
Color rendering issues have occurred, where finishes appear differently under the
courtroom lighting than expected, resulting in changing the lighting or the wood
finishes.
Misunderstandings by the project participants can occur over design issues, often
related to a lack of awareness about lighting design principles and technologies and a
lack of priority for energy efficiency.
2.5 Energy Analysis
The energy analysis first focused on determining the severity of the problems related to energy
usage. To do this, it was necessary to determine the power density for each of the courtrooms
based on the best data available. Once this was done, possible solutions were investigated.
2.5.1. Existing Power Density Analysis
Energy data collection and analysis for the selected courtrooms involved several steps
aimed at assessing the lighting characteristics. The methodology is detailed below, and the
findings are compared against EPAct 2005 requirements.
2.5.1.1. Methodology
For each set of available drawings, those specific to the chosen courtroom were
separated and enlarged to identify room characteristics and lighting fixture codes to
match the lighting schedule where available. Audit data from Arup Lighting was
applied where necessary to supplement missing information. Input wattages were
multiplied by fixture quantities to get overall wattage used, which was then divided by
the square footage to get the lighting power density (LPD) for each courtroom.
March 2006
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