improving student performance with daylighting
DESCRIPTION
By Energy Studies in Buildings LaboratoryPresented to Shanghai Xian Dai Architects at the University of OregonTRANSCRIPT
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
0
10
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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
© 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?