gaudian glasses types

1 3

2 2

21 32 25 94 17 28 28 0.78 0.66 0.34 0.29 78 0.73

23 20 30 98 20 20 33 0.88 0.77 0.42 0.36 94 0.69

34 22 22 95 31 18 43 0.95 0.85 0.52 0.45 117 0.78

38 23 8 92 29 21 40 0.87 0.76 0.48 0.41 106 0.95

51 17 17 98 48 13 58 1.00 0.91 0.69 0.60 151 0.88

20 31 25 94 17 26 28 0.78 0.65 0.35 0.30 79 0.7323 20 30 98 19 19 33 0.88 0.77 0.42 0.36 94 0.69

33 22 22 94 30 17 43 0.94 0.84 0.52 0.45 116 0.79

37 23 8 91 28 20 39 0.87 0.75 0.48 0.41 106 0.95

51 17 17 98 47 13 57 1.01 0.90 0.68 0.59 149 0.89

50 16 17 97 43 12 55 5.5 0.97 0.88 0.66 0.57 145 0.91

49 16 17 96 42 12 54 5.4 0.96 0.87 0.65 0.56 143 0.92

18 26 25 89 12 17 26 0.78 0.66 0.33 0.28 75 0.70

20 17 30 93 13 13 30 0.88 0.77 0.38 0.33 87 0.68

30 18 22 90 21 12 37 0.95 0.85 0.46 0.39 103 0.81

33 19 8 87 20 13 35 0.87 0.76 0.43 0.37 96 0.9645 14 17 93 32 10 47 1.00 0.91 0.56 0.49 125 0.97

17 23 25 86 10 14 25 0.78 0.65 0.32 0.27 74 0.67

19 16 30 90 11 11 28 0.88 0.77 0.37 0.32 85 0.66

28 17 22 87 17 10 35 0.94 0.84 0.43 0.37 99 0.80

31 17 8 84 17 11 33 0.87 0.75 0.41 0.35 92 0.94

42 13 16 90 26 9 43 1.01 0.90 0.52 0.45 117 0.98

Product

Visible Light

Colour Rendering

Index Ra(D65)

Solar Energy European Standards American Standards (NFRC 100 - 2004)

Light to Solar Gain

Trans-mission

%

Reflec-tion

Outside %

Reflec-tion

Inside %

Direct Transmis-

sion %

Reflec-tion

Outside %

Solar Factor,

(g) EN 410 %

U-Value, EN 673

W/(m2K)

Winter SummerU-Value,

Night time BTU/

hr.ft2.F

U-Value, Day time

BTU/

hr.ft2.F

Shading Coefficient

Shading Coefficient

SHGC

Relative Heat Gain BTU/

hr.ft2

Silver 20

Royal Blue 20

Silver Grey 32

Neutral 34

Light Blue 52

Silver 20

Royal Blue 20

Silver Grey 32

Neutral 34

Light Blue 52

Light Blue 52

Monolithic Glass Data, Clear Glass

SunGuard Solar- 4mm Clear Glass Solar Coating #2 Surface

Solar Coating #2 Surface


SunGuard Solar- 6mm Clear Glass


Light Blue 52


Product

Visible Light Solar Energy European Standards American Standards (NFRC 100 - 2004)

Light to Solar Gain

Trans-mission

%

Winter Summer

SHGC

Green 20

Aquamarine 20

Green 32

Green 34

Green 52

Green 20

Aquamarine 20

Green 32

Green 34

Green 52

Colour Rendering

Index Ra(D65)

Reflec-tion

Outside %

Reflec-tion

Outside %

Reflec-tion

Inside %

Direct Transmis-

sion %

Solar Factor,

(g) EN 410 %

U-Value, EN 673

W/(m2K)

U-Value, Night time BTU/

hr.ft2.F

U-Value, Day time

BTU/

hr.ft2.F

Relative Heat Gain BTU/ hr.ft2

Monolithic Glass Data, Green Glass

SunGuard Solar- 4mm Green Glass Solar Coating #2 Surface

SunGuard Solar- 6mm Green Glass Solar Coating #2 Surface


Monolithic glass manufactured exclusively by Guardian Ras Al Khaimah, U.A.E.

4.5

5.0

5.4

5.0

5.7

4.4

5.0

5.3

4.9

5.6

4.5

5.0

5.4

5.0

5.7

4.4

5.0

5.3

4.9

5.6

Insulating Data, Clear Outboard Glass, Configuration: 6mm/12mm A.S./6mm

Product

Visible Light

Colour Rendering

Index Ra(D65)


Trans-mission

%

Reflec-tion

Outside %

Reflec-tion

Inside %

Direct Transmis-

sion %

Reflec-tion

Outside %

Solar Factor,

(g) EN 410 %

U-Value, EN 673

W/(m2K)


Night time BTU/

hr.ft2.F

U-Value, Day time

BTU/

hr.ft2.F

Shading Coefficient

Shading Coefficient

SHGC


hr.ft2

Insulating Data, Green Outboard Glass, Configuration: 6mm/12mm A.S./6mm

Product


Light to Solar Gain

Light to Solar Gain

Trans-mission

%

Winter Summer

SHGC

SunGuard Solar- 6mm green/ 12mm a.s. / 6mm clear Solar Coating #2 Surface


Green 20 15 23 29 85 9 14 17 2.3 0.39 0.41 48 0.91

Aquamarine 20 17 16 33 89 10 11 19 2.5 0.43 0.45 55 0.91

Green 32 25 17 26 86 15 11 24 2.7 0.45 0.48 67 1.03

Green 34 28 18 15 83 15 11 24 2.5 0.42 0.45 63 1.19

Green 52 38 15 22 88 23 9 32 2.8 0.47 0.49 83 1.19

SunGuard Solar- 6mm green/ 12mm a.s. / 6mm clear Solar Coating #2 Surface, Climaguard Neutral 70 # 3 Surface

Green 20 13 23 21 83 7 14 15 1.8 0.33 0.33 41 0.86

Aquamarine 20 14 16 24 87 8 11 16 1.9 0.33 0.34 44 0.90

Green 32 21 17 19 84 12 11 21 1.9 0.33 0.34 54 1.01

Green 34 24 18 11 81 12 11 21 1.9 0.33 0.34 53 1.13

Green 52 32 14 16 87 18 10 28 1.9 0.34 0.34 68 1.15

SunGuard High Performance - 6mm green/ 12mm a.s. / 6mm clear High Performance Coating #2 Surface

Green 35 28 31 23 90 14 18 20 1.6 0.30 0.29 49 1.42

Green 40 33 18 12 83 17 12 23 1.7 0.31 0.31 56 1.42

Aquamarine 40 32 19 23 87 15 14 21 1.7 0.31 0.30 53 1.48

Green Plus 50 40 19 20 87 19 14 25 1.6 0.29 0.29 59 1.62

Green 60 46 18 14 87 23 12 29 1.7 0.30 0.30 68 1.58

Green 70 56 10 12 87 31 8 37 1.9 0.34 0.34 87 1.51

Colour Rendering

Index Ra(D65)

Reflec-tion

Outside %

Reflec-tion

Outside %

Reflec-tion

Inside %

Direct Transmis-

sion %

Solar Factor,

(g) EN 410 %

U-Value, EN 673

W/(m2K)


hr.ft2.F

U-Value, Day time

BTU/

hr.ft2.F


SunGuard Solar- 6mm clear/ 12mm a.s. / 6mm clear

Silver 20 19 32 29 92 14 27 21 2.3 0.39 0.41 0.26 57 0.88

Royal Blue 20 21 21 33 97 16 19 24 2.5 0.43 0.45 0.30 67 0.85

Silver Grey 32 30 23 26 93 25 18 34 2.7 0.45 0.48 0.40 87 0.91

Neutral 34 34 24 15 90 24 20 31 2.5 0.42 0.45 0.37 80 1.08Light Blue 52 46 19 22 96 39 15 47 2.8 0.47 0.49 0.56 118 0.97

SunGuard Solar- 6mm clear/ 12mm a.s. / 6mm clear Solar Coating #2 Surface, Climaguard Neutral 70 # 3 SurfaceSilver 20 16 31 21 90 11 27 19 1.8 0.33 0.33 0.22 50 0.82

Royal Blue 20 17 20 24 95 12 20 21 1.9 0.33 0.34 0.26 56 0.82

Silver Grey 32 26 22 19 91 19 19 29 1.9 0.33 0.34 0.34 72 0.87

Neutral 34 28 24 12 88 18 21 28 1.9 0.33 0.34 0.32 69 1.01

Light Blue 52 39 18 16 94 28 16 41 1.9 0.34 0.34 0.47 99 0.94

SunGuard High Performance - 6mm clear/ 12mm a.s. / 6mm clear High Performance Coating #2 Surface

Silver 35 34 42 23 97 22 40 26 1.6 0.30 0.29 0.29 63 1.28Neutral 40 39 23 12 90 26 27 31 1.7 0.31 0.31 0.34 73 1.27

Royal Blue 40 38 25 23 94 24 29 29 1.7 0.31 0.30 0.33 70 1.31

Neutral Plus 50 48 26 20 94 29 33 33 1.6 0.29 0.29 0.35 77 1.45

Neutral 60 55 23 15 95 36 29 41 1.7 0.30 0.30 0.44 93 1.35

Climaguard Neutral 70 67 12 12 95 49 15 56 1.9 0.34 0.34 0.62 128 1.21

SunGuard High Selective - 6mm clear/ 12mm a.s. / 6mm clear High Selective Coating #2 SurfaceSuper Neutral 40 39 16 31 90 21 36 24 1.6 0.29 0.28 0.26 56 1.62

Super Neutral 51 50 12 22 92 25 37 29 1.6 0.29 0.28 0.30 64 1.75

Super Neutral 62 62 14 17 94 31 38 34 1.6 0.29 0.28 0.36 75 1.80

Super Neutral 70 69 11 12 95 37 34 41 1.6 0.29 0.28 0.43 91 1.67

0.23

0.27

0.35

0.32

0.49

0.20

0.23

0.30

0.28

0.41

0.26

0.30

0.29

0.32

0.39

0.54

0.23

0.26

0.31

0.38

0.19

0.22

0.27

0.25

0.34

0.16

0.18

0.22

0.22

0.28

0.20

0.23

0.22

0.24

0.28

0.36

0.21

0.24

0.30

0.29

0.38

0.18

0.20

0.24

0.24

0.32

0.22

0.26

0.25

0.28

0.32

0.41

Product

Visible Light

Colour Rendering

Index Ra(D65)


Light to Solar Gain

Trans-mission

%

Reflec-tion

Outside %

Reflec-tion

Inside %

Direct Transmis-

sion %

Reflec-tion

Outside %

Solar Factor,

(g) EN 410 %

U-Value, EN 673

W/(m2K)


Night time BTU/

hr.ft2.F

U-Value, Day time

BTU/

hr.ft2.F

Shading Coefficient

Shading Coefficient

SHGC


hr.ft2

Silver 20

Royal Blue 20

Silver Grey 32

Neutral 34

Light Blue 52

Silver 20Royal Blue 20

Silver Grey 32

Neutral 34

Light Blue 52

Silver 35

Neutral 40

Royal Blue 40

Neutral Plus 50

Neutral 60

Climaguard Neutral 70

Super Neutral 40

Super Neutral 51

Super Neutral 62

Super Neutral 70


SunGuard Solar- 8mm clear/ 12mm a.s. / 6mm clear Solar Coating #2 Surface

18 31 29 92 14 25 21 2.3 0.39 0.41 57 0.88

21 20 33 96 16 18 24 2.5 0.43 0.45 67 0.86

30 22 26 93 25 17 33 2.7 0.45 0.47 86 0.92

33 24 15 90 23 19 31 2.5 0.42 0.44 80 1.09

45 19 22 96 38 14 46 2.8 0.46 0.49 116 0.99

SunGuard Solar- 8mm clear/ 12mm a.s. / 6mm clear Solar Coating #2 Surface, Climaguard Neutral 70 # 3 Surface

15 31 21 90 11 25 19 1.8 0.32 0.33 49 0.82

17 20 24 94 12 19 21 1.9 0.33 0.33 55 0.83

25 22 19 91 18 18 29 1.9 0.33 0.34 71 0.88

28 23 12 88 18 20 28 1.9 0.33 0.33 68 1.02

38 18 16 94 28 16 40 1.9 0.33 0.34 97 0.95

SunGuard High Performance - 8mm clear/ 12mm a.s. / 6mm clear High Performance Coating #2 Surface

34 41 23 97 22 37 26 1.6 0.30 0.29 62 1.29

39 23 12 89 25 25 30 1.7 0.31 0.31 72 1.28

38 25 23 94 23 27 29 1.7 0.31 0.30 69 1.33

48 25 20 94 28 31 33 1.6 0.29 0.29 76 1.46

54 23 15 95 35 27 40 1.7 0.30 0.30 91 1.37

67 12 12 94 48 14 54 1.9 0.33 0.34 125 1.23

SunGuard High Selective - 8mm clear/ 12mm a.s. / 6mm clear High Selective Coating #2 Surface

39 16 31 90 20 34 24 1.6 0.29 0.28 56 1.61

50 12 22 91 25 35 28 1.6 0.29 0.28 64 1.75

61 14 17 93 31 35 34 1.6 0.29 0.28 75 1.80

68 11 12 95 37 32 41 1.6 0.29 0.28 90 1.67

Product


Light to Solar Gain

Trans-mission

%

Winter Summer

SHGC

Green 20

Aquamarine 20

Green 32

Green 34

Green 52

Green 20

Aquamarine 20

Green 32

Green 34

Green 52

Green 35

Green 40

Aquamarine 40

Green Plus 50

Green 60

Green 70

Colour Rendering

Index Ra(D65)

Reflec-tion

Outside %

Reflec-tion

Outside %

Reflec-tion

Inside %

Direct Transmis-

sion %

Solar Factor,

(g) EN 410 %

U-Value, EN 673

W/(m2K)


hr.ft2.F

U-Value, Day time

BTU/

hr.ft2.F




14 21 29 82 8 12 16 2.3 0.39 0.41 47 0.90

16 15 33 86 8 10 18 2.5 0.43 0.45 52 0.91

24 16 26 83 13 9 22 2.7 0.45 0.47 63 1.05

26 16 15 80 13 10 22 2.5 0.42 0.44 60 1.20

35 13 22 85 19 9 29 2.8 0.46 0.49 77 1.23SunGuard Solar- 8mm green/ 12mm a.s. / 6mm clear Solar Coating #2 Surface, Climaguard Neutral 70 # 3 Surface

High Performance Coating #2 Surface

12 21 21 80 6 12 14 1.8 0.32 0.33 39 0.86

13 14 24 84 7 10 15 1.9 0.33 0.33 42 0.90

20 15 19 81 10 9 19 1.9 0.33 0.34 50 1.04

22 16 11 78 11 10 19 1.9 0.33 0.33 50 1.14

30 13 16 84 15 9 25 1.9 0.33 0.34 62 1.20SunGuard High Performance - 8mm green/ 12mm a.s. / 6mm clear

26 27 23 87 12 15 18 1.6 0.30 0.29 46 1.44

30 16 12 80 15 10 21 1.7 0.31 0.31 52 1.45

30 17 22 84 14 11 20 1.7 0.31 0.30 50 1.51

37 17 20 84 17 11 23 1.6 0.29 0.29 55 1.65

42 16 14 84 20 11 26 1.7 0.30 0.30 62 1.63

52 9 12 84 26 7 33 1.9 0.33 0.34 78 1.58

0.23

0.27

0.35

0.32

0.48

0.20

0.22

0.29

0.28

0.40

0.26

0.30

0.29

0.32

0.38

0.53

0.23

0.26

0.31

0.38

0.26

0.30

0.40

0.37

0.55

0.22

0.25

0.33

0.32

0.46

0.29

0.34

0.33

0.35

0.44

0.60

0.26

0.30

0.36

0.43

0.18

0.21

0.25

0.24

0.31

0.16

0.17

0.20

0.20

0.25

0.19

0.21

0.20

0.23

0.26

0.32

0.20

0.23

0.28

0.27

0.35

0.17

0.19

0.23

0.23

0.29

0.21

0.24

0.23

0.25

0.29

0.37


Product

Visible Light

Colour Rendering

Index Ra(D65)

Solar Energy European Standards

European Standards

American Standards (NFRC 100 - 2004)

Trans-mission

%

Reflec-tion

Outside %

Reflec-tion

Inside %

Direct Transmis-

sion %

Reflec-tion

Outside %

Solar Factor,

(g) EN 410 %

U-Value, EN 673

W/(m2K)


Night time BTU/

hr.ft2.F

U-Value, Day time

BTU/

hr.ft2.F

Shading Coefficient SHGC


hr.ft2

Light to Solar Gain

Solar Coating #2 SurfaceSunGuard Solar- 8mm clear/ 12mm a.s. / 8mm clear

Silver 20

Royal Blue 20

Silver Grey 32

Neutral 34

Light Blue 52

SunGuard Solar- 8mm clear/ 12mm a.s. / 8mm clear Solar Coating #2 Surface, Climaguard Neutral 70 # 3 SurfaceSilver 20

Royal Blue 20

Silver Grey 32

Neutral 34

Light Blue 52

SunGuard High Performance - 8mm clear/ 12mm a.s. / 8mm clear High Performance Coating #2 SurfaceSilver 35

Neutral 40

Royal Blue 40

Neutral Plus 50

Neutral 60

Climaguard Neutral 70

SunGuard High Selective - 8mm clear/ 12mm a.s. / 8mm clear High Selective Coating #2 SurfaceSuper Neutral 40

Super Neutral 51

Super Neutral 62

Super Neutral 70

14 21 28 82 7 12 16 0.39 0.41 0.20 0.28 46 0.90

16 14 32 85 8 10 17 0.42 0.45 0.23 0.21 52 0.91

23 16 25 82 13 9 22 0.45 0.47 0.28 0.25 62 1.05

26 16 15 79 13 10 22 0.42 0.44 0.27 0.24 60 1.19

35 13 21 85 19 9 29 0.46 0.49 0.35 0.31 76 1.23

12 21 21 80 6 12 14 0.32 0.33 0.17 0.18 39 0.85

13 14 24 84 6 10 15 0.33 0.33 0.19 0.17 42 0.90

20 15 19 80 10 9 19 0.33 0.34 0.23 0.20 50 1.03

22 16 11 78 10 10 19 0.33 0.33 0.23 0.20 50 1.14

30 13 16 83 15 9 25 0.33 0.34 0.29 0.25 62 1.19

26 27 23 86 12 15 18 0.29 0.29 0.21 0.18 46 1.43

30 16 12 79 15 10 21 0.31 0.31 0.24 0.21 52 1.44

29 17 22 84 13 11 20 0.30 0.30 0.23 0.20 50 1.50

37 17 20 83 17 11 23 0.29 0.29 0.25 0.22 55 1.64

42 16 14 84 20 11 26 0.30 0.30 0.29 0.25 62 1.62

52 9 11 84 26 7 33 0.33 0.34 0.36 0.32 78 1.57

Shading Coefficient


Product

Visible Light Solar Energy American Standards (NFRC 100 - 2004)

Light to Solar Gain

Trans-mission

%

Winter Summer

SHGC


Green 20

Aquamarine 20

Green 32

Green 34

Green 52

SunGuard Solar- 8mm green/ 12mm a.s. / 8mm clear Solar Coating #2 Surface, Climaguard Neutral 70 # 3 Surface

Green 20

Aquamarine 20

Green 32

Green 34

Green 52

SunGuard High Performance - 8mm green/ 12mm a.s. / 8mm clear High Performance Coating #2 Surface

Green 35

Green 40

Aquamarine 40

Green Plus 50

Green 60

Green 70

Colour Rendering

Index Ra(D65)

Reflec-tion

Outside %

Reflec-tion

Outside %

Reflec-tion

Inside %

Direct Transmis-

sion %

Solar Factor,

(g) EN 410 %

U-Value, EN 673

W/(m2K)


hr.ft2.F

U-Value, Day time

BTU/

hr.ft2.F


18 31 28 91 13 25 21 2.3

2.5

2.7

2.5

2.8

1.8

1.9

1.9

1.9

1.9

1.6

1.7

1.7

1.6

1.7

1.9

1.6

1.6

1.6

1.6

2.3

2.5

2.7

2.5

2.8

1.8

1.9

1.9

1.9

1.9

1.6

1.7

1.7

1.6

1.7

1.9

0.39 0.41 0.26 0.23 57 0.88

20 20 32 95 15 18 24 0.42 0.45 0.30 0.26 66 0.86

30 22 26 92 24 17 32 0.45 0.47 0.39 0.34 85 0.92

33 24 15 89 22 19 30 0.42 0.44 0.36 0.32 79 1.09

45 19 22 95 37 14 45 0.46 0.49 0.54 0.47 115 0.99

15 31 21 89 10 25 19 0.32 0.33 0.22 0.20 49 0.82

17 20 24 94 11 19 21 0.33 0.33 0.25 0.22 55 0.83

25 22 19 90 18 18 28 0.33 0.34 0.33 0.29 71 0.88

28 23 11 87 17 20 27 0.33 0.33 0.32 0.28 68 1.02

38 18 16 93 27 16 40 0.33 0.34 0.46 0.40 96 0.95

33 41 23 96 21 37 26 0.29 0.29 0.29 0.25 62 1.28

39 23 12 89 25 25 30 0.31 0.31 0.34 0.29 71 1.27

38 25 22 94 23 27 28 0.30 0.30 0.32 0.28 69 1.32

48 25 20 93 28 31 33 0.29 0.29 0.35 0.31 76 1.45

54 23 14 94 34 27 40 0.30 0.30 0.43 0.38 91 1.36

66 12 12 94 47 14 54 0.33 0.34 0.60 0.52 125 1.23

39 16 31 89 20 34 24 0.29 0.28 0.26 0.23 56 1.60

49 12 22 91 24 35 28 0.29 0.28 0.30 0.26 64 1.74

61 14 17 93 30 35 34 0.29 0.28 0.36 0.31 75 1.79

68 11 11 95 36 32 41 0.29 0.28 0.43 0.38 90 1.66

L O W- E C O AT I N G S

Relatively neutral in appearance, low-E coatings reduce heat gain or loss by reflecting long-wave infrared energy

(heat) and, therefore decrease the U-Value and improve energy efficiency.

Current sputter-coated low-E coatings are multilayered, complex designs engineered to provide high visible light

transmission, low visible light reflection and reduce heat transfer. SunGuard Silver 35, Neutral 40, Royal Blue 40,

Neutral Plus 50, Neutral 60 and ClimaGuard Neutral 70 are all Low-E coatings.

R EL AT I V E H E AT G A I N ( R H G )

The total heat gain through glass for a specific set of conditions. This value considers indoor/

outdoor air temperature differences and the effect of solar radiation. The units are

Btu/hr.ft². RHG = [(89°F - 75°F)(Summer U-Value) + (200 Btu/hr.ft²)(Shading Coefficient)]

R - VA L U E

A measure of the resistance of the glazing to heat flow. It is determined by dividing the U-Value into 1,

(R-Value = 1/U-Value). A higher R-Value indicates better insulating properties of the glazing.

R-Value is not typically used as a measurement for glazing products and is referenced here to help

understand U-Value.

S H A D I N G C O E F F I C I EN T ( S C ) - N F RC - 1 0 0 - 20 0 4

An alternative measure of the heat gain through glass from solar radiation. Specifically, the shading coefficient is

the ratio between the solar heat gain for a particular type of glass and that of double-strength clear glass. A lower

shading coefficient indicates lower solar heat gain. For reference, 1/8" (3.1 mm) clear glass has a value of 1.00.

(SC is an older term being replaced by the SHGC).

S O L A R C O N VE R S I O N S

• Solar Energy Transmittance

• Solar Heat Gain Coefficient/0.86

• Total Solar Transmittance - Direct Solar Transmittance

• 1 - Direct Solar Transmittance - Solar Reflectance

Units of Measure

U-Value

5.6783

4.887

BTUhr.ft2.F

x

= Kcalhr.m2.C

Wm2K

=

BTUhr.ft2.F

x

Relative Heat Gain

3.1525

2.715

BTUhr.ft2 x

= Kcalhr.m2

Wm2=

BTUhr.ft2 x

Relative Heat Gain

3.1525BTUhr.ft2 hr.m2x W

m2= 2.715BTUhr.ft2 x Kcal

=

SOLAR ENERGY

Radiant energy from the sun having a wavelength range of 300 to

4000 nm, which includes UV (300 to 380 nm), visible light (380 to

780 nm) and near infrared energy (780 to 4000 nm).

• – percentage of incident solar energy

directly reflected from the glass back outdoors.

• – percentage of incident solar energy

absorbed into the glass.

• – percentage of incident solar energy directly

transmitted through the glass.

smittance = 100%. An additional

consideration is emission, or emissivity. This refers to the reradiation of absorbed energy that

can be emitted toward both the exterior and interior of the building. Emissivity is controlled

through the use of low-emissivity, or low-E coatings.

S O L A R H E AT G A I N C O E F F I C I EN T ( SH G C ) - N F RC - 1 0 0 - 2 00 4

The percent of solar energy incident on the glass that is transferred indoors, both directly and

indirectly through the glass. The direct gain portion equals the solar energy transmittance, while the

indirect is the fraction of solar incident on the glass that is absorbed and re-radiated or convected

indoors. For example, 1/8" (3.1 mm) uncoated clear glass has a SHGC of approximately 0.86, of which

0.84 is direct gain (solar transmittance) and 0.02 is indirect gain (convection/re-radiation).

S O L A R / R EF L E C T I VE C O AT I N G S

Typically, highly reflective coatings that reduce solar heat gain through reflection and absorption.

Though very effective at reducing heat gain, visible light transmittance is generally low and U-Values

are not as energy efficient as low-E coatings. Guardian offers SunGuard Silver 20 and Silver 32 in this

product category.

S P EC T R A L LY SEL EC T I V E G L A Z I N G

High-performance glazing that admits as much daylight as possible, while preventing transmission of

as much solar heat as possible. By controlling solar heat gain in summer, preventing loss of interior

heat in winter, and allowing occupants to reduce electric lighting use by making maximum use of

daylight, spectrally selective glazing significantly reduces building energy consumption. The United

States Department of Energy has established a Light-to-Solar Gain Ratio of 1.25 as the minimum

measurement to be classified as a “Spectrally Selective Glazing”. The calculation of spectrally

selective glazing follows the formula described in the Light-to-Solar Gain definition.

S O L A R FA C T O R = ( G - VA L UE )

Percentage of total solar energy (direct and indirect or absorbed) transferred indoors through the glass.

3mm clear glass has a g-value of approximately 86 and a shading

Absorptance

Reflectance

Transmittance

Solar Energy Physics

Solar

T R A N S M I T TA N C E PE RC E N T

Percentage of incident ultraviolet energy that is directly transmitted through the glass. Long-term

exposure to UV light may result in fabric and pigment fading, plastic deterioration and changes to the

appearance of many types of wood.

U V

Ultraviolet radiant energy from the sun having a wavelength range of 300 to 380 nm with air

mass of 1.5.

U - VA L U E ( U- FA C T O R ) - N F RC - 1 00 - 2 0 04

A measure of the heat gain or loss through glass due to the difference between indoor and outdoor air

temperatures. It is also referred to as the overall coefficient of heat transfer. A lower U-Value indicates

better insulating properties. The units are Btu/(hr)(ft2)(°F).

U - VA L U E = ( K - VA L U E) - E N 67 3 : 1 997

Air to air thermal conductance of the glass and associated air films. The units are W/m2K. Standard

conditions: 10°C gap temperature, 15°C difference across gap, surface coefs. of 23W/m2K outdoor

and 8 indoor. The lower the number the better.

V I S I B L E L I G H T

Radiant energy in the wavelength range of 380 nm to 780 nm with Ill. D65 and CIE 2° observer.

• – percentage of incident visible light directly transmitted through the glass.

• – percentage of incident visible light directly reflected from the glass

back indoors.

• – percentage of incident visible light directly reflected from the glass

back outdoors.

Units of Measure

U-Value

5.6783

4.887

BTUhr.ft2.F

x

= Kcalhr.m2.C

Wm2K

=

BTUhr.ft2.F

x

Relative Heat Gain

3.1525

2.715

BTUhr.ft2 x

= Kcalhr.m2

Wm2=

BTUhr.ft2 x

gaudian glasses types

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