Skylight and Window Glass Performance

Natural Spaces Skylight Performance Data (glass portion only – in vertical position)
Glass type & color
% Daylight
Transmitted
U-Value
Winter
R-Value
Center of Glass
Relative Heat
Gain BTU/hr/sf
% UV
Blocked
Clear double pane
81%
0.48
2.04
182
36%
Bronze tint dbl pane
53%
0.48
2.04
135
68%
Grey tint dbl pane
45%
0.48
2.04
131
62%
Solarcool (mirror)grey,dbl #2
16%
0.48
2.08
85
93%
           
Clear dbl pane Low-E #3
73%
0.34
2.86
167
50%
Bronze tint dbl pane Low-E #3
44%
0.34
2.86
115
77%
Grey tint dbl pane Low-E #3
37%
0.34
2.86
111
73%
Solarcool (mirror) gry, dbl, Low-E #3
14%
0.34
2.94
63
96%
           
Clear dbl pane Low-E #3 Argon
73%
0.29
3.33
167
50%
Bronze tint dbl pane Low-E #3 Argon
44%
0.29
3.33
115
77%
Grey tint dbl pane Low-E #3 Argon
37%
0.29
3.33
111
73%
Solarcool (mirror) gry, dbl, Low-E #3 Argon
14%
0.29
3.33
63
96%
           
Clear dbl, 2 layers, Low-E, Argon
 
0.27
3.70
   
           
Clear triple pane
65%
0.29
3.45
145
 
Bronze tint triple pane
37%
0.29
3.45
96
 
Grey tint triple pane
29%
0.29
3.45
92
 
Solarcool mirror triple pane #2
12%
0.27
3.70
59
 
           
Clear triple, Low-E #5 Argon
57%
0.21
4.76
99
 
Bronze, triple, Low-E #5 Argon
32%
0.21
4.76
67
 
Grey, triple, Low-E #5 Argon
27%
0.21
4.76
63
 
Clear, triple, 2 Low-E Argon
 
0.16
6.25
   
           
Marvin Windows Performance Data (Casement) Based on LoE3-366 glass with argon gas
Glass type & color
% Visable Light
Transmitted
U-Value
(total unit)
R-Value
(total unit)
Solar Heat
Gain Coefficient
 
Clear dbl, Low-E 366, Argon 3/4″ (Intergrity)
46%
0.28
3.57
.20
 
Triple, High-R, Low-E 272, Argon 1″ (Ultimate)
39%
0.23
4.30
.24
 
           
VELUX Roof Windows and Skylight Performance Data (based on 2010 models using LoE3-366 glass)
Glass type & color
% Visable Light
Transmitted
U-Value
(total unit)
R-Value
(total unit)
Solar Heat
Gain Coefficient
% UV
Blocked
VSEand VS Units: Clear dbl, Low-E 3, Argon
         
Tempered over tempered glass (05)
54%
0.43
2.33
.23
95.2%
Tempered over laminated glass (04)
53%
0.42
2.50
.23
99.9%
           
FS Units: Clear dbl, Low-E 2, Argon
         
Tempered over tempered glass (05)
61%
0.45
2.70
.26
95.2%
Tempered over laminated glass (04)
60%
0.44
2.60
.26
99.9%
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