Environmental Controls I/IG
Lecture 18
Daylighting Design & Analysis
Design Strategies
Glazing and Reflectors
Sidelighting Analysis Method
Daylighting
Design & Analysis
Orientation and Slope
Vertical vs. Horizontal
Time of year
Sun position
DL-5 F. 10-1 p. 79
Daylighting Components
SC=Sun + Sky
IRC1
IRC2
ERC
S: F.14.18 p. 590
Daylighting Factor (DF)
The quantity of interior illuminance on a
horizontal work plane expressed as a
percentage of illuminance of an exterior
unobstructed horizontal plane
DF (%) = (EINT/EEXT) x 100
Daylighting Factor (DF)
If EINT is 20 foot-candles
and EEXT is 1000 foot-candles,
then what is the daylighting factor?
DF(%)= (EINT/EEXT) x 100
DF (%)=(20/1000) x 100
DF (%)=2.0%
Isolux Contours


Lines of similar
lighting levels
Expressed as DF
Darwin College Library, Cambridge, England
Isolux Contours Example
EEXT= 2000 fc
1: 20 fc
2: 60 fc
3: 100 fc
4: 40 fc
5: 80 fc
6: 140 fc
7: 20 fc
8: 60 fc
9: 100 fc
1+
2+
3+
4+
5+
6+
7+
8+
9+
DF(%)= (EINT/EEXT) x 100
Isolux Contours Example
EEXT= 2000 fc
1: 20 fc
2: 60 fc
3: 100 fc
4: 40 fc
5: 80 fc
6: 140 fc
7: 20 fc
8: 60 fc
9: 100 fc
DF=1 %
DF=3 %
DF=5 %
DF=2 %
DF=4 %
DF=7 %
DF=1 %
DF=3 %
DF=5 %
1+
2+
3+
4+
5+
6+
7+
8+
9+
Isolux Contours Example
EEXT= 2000 fc
1: 20 fc
2: 60 fc
3: 100 fc
4: 40 fc
5: 80 fc
6: 140 fc
7: 20 fc
8: 60 fc
9: 100 fc
DF=1 %
DF=3 %
DF=5 %
DF=2 %
DF=4 %
DF=7 %
DF=1 %
DF=3 %
DF=5 %
1
3
5
2
4
7
1
3
2
5
4
6
Isolux Contours


Lines of similar
lighting levels
Expressed as DF
Darwin College Library, Cambridge, England
Illumination
Gradient
An illumination
gradient through
a section
Ludwig Museum, Koln, Germany
Design Strategies
Selection Parameters
Daylight availability
Task orientation
Space orientation
Daylighting Graphs
10’ Ceiling
30” Work plane
DL-5: F10-2 p. 80
South Facing Walls
Solid Overhang
a: translucent glazing
b: horizontal overhang
c: 30º sloped clear
glazing
d: 45º sloped clear
glazing
DL-5: F10-5 p. 82
South Facing Walls
Diffusing Awnings
a: translucent glazing
b: translucent awning
clear glazing
c: white vertical
slatted awning, clear
glazing
d: white, horizontal slatted
awning, clear glazing
DL-5: F10-6 p. 82
Light Shelves
W: With light shelf
WO: Without light shelf
DL-5: F10-18 p. 89
Skylights
Effect of skylight
above roof
a: flat horizontal
b: half-round barrel,
white opaque ends
c: steeply sloped
A-frame, white
opaque ends
Typographic Error In Reading DL-5: F10-21 p. 91
Roof Monitors
North-South
Monitors
a: translucent panel
b: north monitor,
clear glazing
c: south monitor,
translucent
glazing
DL-5: F10-30 p. 95
Roof Monitors
Sun Control
Baffles/Louvers
Light Wells
DL-5: F10-35 p. 97
Roof Monitors
Graphic Design Approach
DL-5: F10-37 p. 98
Glazing & Reflectors
Fenestration
Window or Fenestration?
Clear Glazing
Maximum VLT
DL-5: F11-1 p. 105
Gray/Bronze
Glazing
DL-5: F11-2 p. 106
Gray glass preferred
where color rendition is
important
Heat Absorbing
Glazing
DL-5: F11-3 p. 107


Green is more
common
Blue is becoming
more
available
Solar IR
Reflective Film
DL-5: F 11-6 p. 109
Low-E Glass
Multiple Glazing




Combinations of
individual paned
glazing
Mylar/Film layer
Inert gas (argon or
krypton)
“Superwindow”
Exotics



LED Windows
Aerogels
Kalwall
Prototype House and Studio
Thomas Herzog