Insulating Glass for Residential Glazing, Insulating Glass Unit Thickness, and Dimensional Tolerance

Outboard Lite

Glass
Thickness

Transmittance
Average

Reflectance
Average

(C)
N. America
(ASHRAE)

(D)
Shading
Coefficient

(E)
Solar
Heat Gain
Coefficient

IN

MM

Daylight
%

Solar
%

(B)
UV
%

Daylight
%

Solar
%

Air-Filled
UNIT

Argon-Filled
UNIT

Summer

Winter

Summer

Winter

#3

#2

#3

#2

Clear

3/32
1/8
5/32
3/16
1/4

2.5
3.0
4.0
5.0
6.0

76
75
74
73
72

61
59
56
53
51

49
46
43
40
38

18
18
18
17
17

18
17
16
16
15

0.36
0.36
0.36
0.36
0.36

0.34
0.33
0.33
0.33
0.33

0.30
0.30
0.30
0.30
0.30

0.29
0.28
0.28
0.28
0.28

0.84
0.82
0.80
0.78
0.76

0.77
0.75
0.73
0.71
0.70

0.72
0.71
0.69
0.67
0.65

0.66
0.65
0.63
0.61
0.60

Gray

1/8

3.0

51

40

24

10

11

0.37

0.34

0.31

0.29

0.59

0.51

Bronze

1/8

3.0

57

45

26

12

12

0.36

0.33

0.31

0.28

0.66

0.57

SPACER THICKNESS (IN.)

Glass Thickness (IN.)

3/32

1/8

5/32

3/16

1/4

3/16
1/4
5/16
3/8
7/16
1/2
9/16
5/8
11/16
3/4

3/8
7/16
1/2
9/16
5/8
11/16
3/4
13/16
7/8
15/16

7/16
1/2
9/16
5/8
11/16
3/4
13/16
7/8
15/16
1

1/2
9/16
5/8
11/16
3/4
13/16
7/8
15/16
1
1-1/16

9/16
5/8
11/16
3/4
13/16
7/8
15/16
1
1-1/16
1-1/8

11/16
3/4
13/16
7/8
15/16
1
1-1/16
1-1/8
1-3/16
1-1/4

MONOLITHIC GLASS

INSULATING GLASS

Glass Thickness (IN.)

Length & Width Tolerance (IN.)

Size Range (IN.)

Length & Width Tolerance (IN.)

1/8
3/16
1/4
3/8
1/2
5/8
3/4
1

+/-   1/16
+/-  1/16
+/-  1/16
+/-  3/32
+/-  1/8
+/-  5/32
+/-  3/16
+/-  1/4

To 30
30" to 60
60" to 84
84" & up

+/-  1/8, -1/16
+/-  5/32, -1/16
+/-  3/16, -1/16
Consult Office

Diagonal not to exceed 1/4"

A)

Product Performance Data based on numbers available at the time of publication from Libby-Ownes-Ford, PPG Industries, Inc., and Ford Motor Company. Actual values may vary slightly. HGP reserves the right to change or modify Product Performance Data without notice as new data becomes available. Some combinations or installations may require heat treating to resist glass breaking.

B)

The UV solar transmittance is based on the standard intensity versus wavelength (300 to 400 nanometer; air mass 2.0) for the sun's radiation when the sun is at 60 degree zenith angle and measured at normal incidence to the glass surface.

C)

U-value is the overall coefficient of the heat transmission (air to air) due only to difference in indoor and outdoor temperatures. The lower the U-value, the less heat is transmitted through a material in a given time for a given temperature difference. Winter U-values are based on an outdoor temperature of O°F, an indoor temperature of 70°F and a 15 mph wind velocity with no sun. Summer U-values and Shading Coefficients are based on an outdoor temperature of 89°F, an indoor temperature of 75°F, a solar intensity of 248 Btu/Hr.-Ft, and a 7.5 mph wind velocity. U-values: Btu (hr. x ft.² F). To obtain the Sl (metric). U-value (W/(m² x °C, multiply the North American U-value by 5.678.

D)

Shading Coefficient is the ratio of solar heat gain through a particular product compared to 1/8" (3mm) clear glass. It is based on the same conditions as the summer daytime U-value (see footnote C).

E)

Solar Heat Gain Coefficient represents the solar heat gain through the glass relative to the incident solar radiation. It is equal to 86/87% of the shading coefficient.

F)

Relative Heat Gain - A single value relative product index of overall heat gain. it is based on an ASHRAE solar heat gain factor of 200 Btu/Hr.-Ft and outdoor air 14°F warmer than indoor air. R.H.G. = 200 x (shade coefficient) + 14 x (summer U-value). Relative Heat Gain Units: Btu (hr. x ft.²). To obtain the Sl relative heat gain (W/m²) multiply the North American relative heat gain by 3.154.