GSA
Courtroom Lighting Criteria Evaluation
Task 1 Report
Vertical Illuminance (Fc)
5.4.6
Design Analysis
Horizontal Illuminance (Fc)
120
Other comparisons between the original and revised
scheme and other courthouses are noteable.
110
The contribution of daylight with regards to overall
100
lhi q a t irli ls a ted yg t
i tg u ni s e te m l h alh
g n
t
y
av y
l
i
increases the illuminance levels only 10% to 20% in
90
most positions. However, the subjective feel of the
room when there is daylight is greatly improved with
80
even this small addition of daylight.
70
This courtroom differs from several courtrooms in this
report because the wood panels, even though they
60
are dark, do not extend to the ceiling, allowing a
50
lighter colored wall surface to help brighten the space.
One reason the original scheme failed was the lack of
40
diffuse light. Since all of the lighting in the space was
30
downlighting, the ratio of horizontal to vertical light
w s i oe 51ismecss T icnl dt
a h h vr : n o
g
ae. h a e o
s
a
20
shadowing on faces which can be seen as making
people look worse, even more "r i l Wh nte
ci n "
m a. e h
10
uplight was added, the ratio improved.
0
The addition of downlights at the perimeter provides
added brightness on the walls, however there are
et me"clp" u t tepoii o te
xe
r
sao s d e o h rx t fh
l
my
downlights to the wall. In this situation a linear
wallwash would have been more appropriate in the
original design.
LPD w/sf
5.3
Limit w/sf
1.9
The flexibility of the dimming system for downlights
1
2
3
4
5
and bi-level switching for the fluorescent uplights
allows the users of the room to tune the lighting to
their needs.
Subjective Rating
5
Although the final lighting solution provides a pleasing
4
environment, it was achieved by adding many lights,
3
and hence has the highest overall illuminance levels
2
1
o a y fh cut o s uvydfr vrh
f n o te o ro m sree
r
a oe te
recommendations of the IESNA and the design guide.
Because of the change to tungsten-halogen lighting
and addition of luminaires, this is courtroom likely has
the highest installed lighting power density of the
courtrooms studied.
Note: The table to the right shows data for the revised
lighting scheme. Refer to the table in Section 6 for the
original lighting scheme.
Satisfaction?
NY
Page 23
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