Post on 20-Jul-2016
description
Improving Student Performance with DaylightingStraub Hall, University of Oregon
Why focus on daylighting?
_Daylighting can increase learning and test performance by 20-26% _Glare reduces performance by 15% _Daylit classrooms reduce absenteeism _Daylighting reduces energy use
How much energy can be saved?
_Electric lighting accounts for 20% of all building energy usage _Lower required light levels need less glazing
© 2007, Energy Studies in Buildings Laboratory, University of Oregon
Annual lighting energy saved during daylight hours in Portland, OR with a 5% minimum dimming ballast
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0.0% 1.0% 2.0% 3.0% 4.0% 5.0% 6.0% 7.0% 8.0% 9.0% 10.0%
Daylight factor
Per
cent
lighti
ng e
ner
gy s
avin
gs
5fc
10fc
20fc
30fc
50fc
© 2007, Energy Studies in Buildings Laboratory, University of Oregon
Annual lighting energy saved during daylight hours in Portland, OR with a 5% minimum dimming ballast
0
10
20
30
40
50
60
70
80
90
100
0.0% 1.0% 2.0% 3.0% 4.0% 5.0% 6.0% 7.0% 8.0% 9.0% 10.0%
Daylight factor
Per
cent
lighti
ng e
ner
gy s
avin
gs
5fc
10fc
20fc
30fc
50fc
© 2007, Energy Studies in Buildings Laboratory, University of Oregon
Annual lighting energy saved during daylight hours in Portland, OR with a 5% minimum dimming ballast
0
10
20
30
40
50
60
70
80
90
100
0.0% 1.0% 2.0% 3.0% 4.0% 5.0% 6.0% 7.0% 8.0% 9.0% 10.0%
Daylight factor
Per
cent
lighti
ng e
ner
gy s
avin
gs
5fc
10fc
20fc
30fc
50fc
More Windows
Mor
e En
ergy
Sav
ings
Straub Hall
What was the initial design?
_Large skylights _View windows to the south and north _Clerestory to the east _Deep acoustic clouds _No light under mezzanine
North
How to test the daylighting?
_TheArtificialSkyisamirrorbox that simulates overcast sky conditions _Photometric sensors are placed inside of a scale model to determine daylight intensity and distribution in a space _Interiorsurfacereflectancesare simulated with papers of similar reflectances
interior light levelexteriorlightlevel
=Daylight Factor (DF)
interior sensors
exteriorsensor
Plan
Balcony Plan
6+ 0-1Daylight Factor
5-6 4-5 3-4 2-3 1-2
Section
© 2013 Energy Studies in Buildings Laboratory, University of Oregon
Straub Hall - Lecture HallDaylighting Analysis
2 Linear SkylightsTotal Skylight Area: 500 sf
Iteration #1
_Large skylights creating “hot spots” _Too much light on screen _Deep lightwells reduces daylight _Adequate daylight
Presentation Board
Plan
Balcony Plan
6+ 5-6 4-5 3-4 2-3 1-2 0-1Daylight Factor
Section
© 2013 Energy Studies in Buildings Laboratory, University of Oregon
Straub Hall - Lecture HallDaylighting Analysis
2 Linear SkylightsTotal Skylight Area: 500 sf
Iteration #2
_Small skylights reduce “hot spots” _Screen is adequately darkened _Deep lightwells reduce daylight _Front seats are too dark
Presentation Board
Plan
Balcony Plan
6+ 5-6 4-5 3-4 2-3 1-2 0-1Daylight Factor
Iteration #3
_Small skylights reduce “hot spots” _Screen is slightly too bright _Shallow lightwells increase daylight _Adequate daylight in all seating
Presentation Board
Plan
Balcony Plan
6+ 5-6 4-5 3-4 2-3 1-2 0-1Daylight Factor
Iteration #4
_Small skylights reduce “hot spots” _Screen is adequately darkened _Shallow lightwells increase daylight _Adequate daylight in all seating
Presentation Board
How to control the daylight levels?
_Different space uses require different lighting levels _Daylight levels vary with seasonal and daily climate
_Adaptable shading is required!
How to adapt the shading?
_Louvers are integrated into the skylights to instantaneously adjust to maintain light levels _Automated cloth shades on vertical glazing block daylight while retaining views out _Daylight sensors adjust electric lighting levels under mezzanine to match the daylight levels in the rest of space
Vertical Glazing: 0% Open
Vertical Glazing: 0% Open
Vertical Glazing: 100% Open
Vertical Glazing: 0% Open
WINTER SUMMER
Figure 2: Current Visible Transmission (Vt_vertical=75%, Vt_skylight=52%)
Average: 1.6 fc
Average: 1.4 fc
Max: 0.3 fc
Average: 3.0 fc
Average: 1.5 fc
Max: 0.5 fc
Average: 8.5 fc
Average: 3.2 fc
Max: 5.0 fc
Average: 6.3 fc
Average: 6.0 fc
Max: 1.6 fc
Values represent overcast conditions only
15752:da Copyright 2013, Energy Studies in Buildings Laboratory, University of Oregon
Middle & Front Skylights: 50% Open
Middle & Front Skylights: 0% Open
Middle & Front Skylights: 100% Open
Middle & Front Skylights: 67% Open
Back Skylights: 0% Open
Back Skylights: 100% Open
Back Skylights: 0% Open
Back Skylights: 0% Open
FEAT
UR
E PR
ESEN
TATI
ON
S (1
FC
)AV
WIT
H N
OTE
TA
KIN
G (5
FC
)
Vertical Glazing: 0% Open
Vertical Glazing: 0% Open
Vertical Glazing: 100% Open
Vertical Glazing: 0% Open
WINTER SUMMER
Figure 2: Current Visible Transmission (Vt_vertical=75%, Vt_skylight=52%)
Average: 1.6 fc
Average: 1.4 fc
Max: 0.3 fc
Average: 3.0 fc
Average: 1.5 fc
Max: 0.5 fc
Average: 8.5 fc
Average: 3.2 fc
Max: 5.0 fc
Average: 6.3 fc
Average: 6.0 fc
Max: 1.6 fc
Values represent overcast conditions only
15752:da Copyright 2013, Energy Studies in Buildings Laboratory, University of Oregon
Middle & Front Skylights: 50% Open
Middle & Front Skylights: 0% Open
Middle & Front Skylights: 100% Open
Middle & Front Skylights: 67% Open
Back Skylights: 0% Open
Back Skylights: 100% Open
Back Skylights: 0% Open
Back Skylights: 0% Open
FEAT
UR
E PR
ESEN
TATI
ON
S (1
FC
)AV
WIT
H N
OTE
TA
KIN
G (5
FC
)How much shading is needed? _The vertical glazing contributes daylight differently than the skylights, so the vertical glazing is shaded differently than the skylights
A better space for learning?