Tehnical Information North Canterbury Glass Rangiora Christchurch New Zealand
North Canterbury Glass Rangiora New Zealand

Technical Information | An In Depth Analysis

All anyone could ever want to know about glass and its many properties.

UV Elimination
The percentage of ultraviolet light eliminated by the glass type, below the 380 nanometer wavelength range.

Light Transmission
The percentage of light that passes through the particular glass type, measured against 100% light outside the building.

Light Reflection
The percentage of light reflected by the exterior surface of the particular glass type.

Shading Coefficient
A measurement of the ratio of total solar heat transmission of a particular glass type compared with 3mm clear glass: the % total heat transmission of the chosen glass, divided by 87

U Value
A measure of the rate of thermal transmittance through glass, which is directly related to the weather conditions. Usually determined using conditions established by ASHRAE(American Society of Heating, Refrigeration and Air Conditioning Engineers). The lower the U-value, the lower the thermal transmittance and hence the better the insulation.

Summer U-value
a measure of heat gain - the amount of heat transmitted into a building. Determined using the midday summer weather conditions(ASHRAE)

Winter U-value
a measure of heat loss - the amount of heat loss by a building. Determined using midnight winter weather conditions(ASHRAE winter).

r Value
Thermal resistance = r value (W/m2 / Co). r value is the opposite measurement to U value, measuring resistance to heat loss, rather than the transmission through glass. The higher the r value the better the insulation.

dB Value
Decibels are the measure of sound intensity. Two systems measure sound reduction in buildings: Sound Transmission Loss (STL) and Sound Transmission Class (STC). The higher the dB Value the better the sound insulation.

Emissivity
A materials ability to radiate energy. Used to measure effectiveness of a glass coating - the lower the emissivity the better the glass performs in reducing heat transfer.

Low E
Low emissivity - refers to glass designed to reduce heat transfer. Usually nonreflective and highly transparent. Most efficient in double glazing.

Don't let your valuables fade away!
Fading is the enemy of the home maker, furniture, drapes, carpets, even artworks and photos all come under attack. But you can significantly reduce fading by careful selection of glass. Research shows up to 92% of furniture fading is caused by solar energy: 40% UV radiation , visible light: 27%, infrared radiation (in effect heat) 25%. Some 8% comes from humidity, pollutants, etc UV radiation fades directly, sunlight and infrared both heat the fabric which accelerates the fading process. It makes sense to use glass which diminishes solar energy, by absorbing or reflecting the light culprits. Its like putting up a sunscreen. UV radiation is controlled by laminates, the PVB 'glue' inter layer absorbing up to 99% of the radiation. Tinted glasses will reflect and absorb visible light and heat. So an optimum answer is to use tinted laminate or a double glaze unit consisting of clear laminate and tinted float.
North Canterbury Glass Rangiora Shapes

 

Fading Reduction Percentages

Glass Type Size % fading reduction % UV fading elimination
Clear Float 3mm 0 27
  4mm 0 30
  5mm 0 35
  6mm 0 43
  10mm 16 46
Clear Low E 4mm 20 46
  6mm 26 51
Grey Float 5mm 53 71
  6mm 60 76
  10mm 71 87
Bronze Float 5mm 51 70
  6mm 58 75
Evergreen 6mm 62 86
Stopsol SS Grey 6mm 74 85
Stopsol Bronze 6mm 84 93
Stopsol SS Dark Blue 6mm 62 79
Azur Blue/Green 6mm 41 72
SunergyAzurBlue/Green 6mm 62 79
Sunergy Green 6mm 65 86
Comfortplus / Solar E 6mm 35 57
Panasap Dark Green 6mm 62 86
Panasap Dark Blue 6mm 45 71
Panasap Dark Grey 6mm 60 74
Clear Laminated 6.38mm 47 99
  10.38mm 49 99
Grey Laminated 6.38mm 91 99
North Canterbury Glass Rangiora How Glass Breaks
Single Glazing Performance

Glass Type

Size

LT % light
transmission

LR % light reflection

TS % total solar heat transmission

Shading coefficient

Clear Float

3mm

90

8

82

1.00

 

4mm

89

8

80

0.98

 

5mm

89

8

79

0.96

 

6mm

88

7

76

0.94

 

10mm

86

7

69

0.88

Clear Low E

4mm

83

12

68

0.84

 

6mm

82

12

65

0.80

Grey Float

4mm

56

6

53

0.76

 

5mm

50

6

47

0.71

 

6mm

44

6

41

0.66

 

10mm

28

5

25

0.55

Bronze Float

4mm

63

6

59

0.80

 

5mm

56

6

54

0.77

 

6mm

53

6

49

0.72

Panasap Dark Green

6mm

66

5

33

0.06

 

10mm

58

6

45

0.53

Panasap Dark Blue

6mm

58

6

58

0.66

Panasap Dark Grey

6mm

16

5

52

0.60

Evergreen

6mm

66

5

33

0.60

Stopsol SS Grey Coat Out

6mm

32

30

47

0.54

Stopsol SS Grey Coat In

6mm

32

11

44

0.51

Stopsol Bronze Coat Out

6mm

21

34

40

0.46

Stopsol Bronze Coat In

6mm

21

13

27

0.53

Stopsol SS Dark Blue Coat Out

6mm

41

30

44

0.51

Stopsol SS Dark Blue Coat In

6mm

41

15

47

0.54

Azur Blue/Green

6mm

71

5

34

0.60

Sunergy Azur Blue/Green Coat In

6mm

56

7

45

0.52

Sunergy Green Coat In

6mm

55

7

42

0.48

Comfortplus / Solar E Coat In

6mm

61

10

44

0.61

Diamant / Starfire

6mm

91

8

88

1.03

 

10mm

91

8

86

1.02

Clear Laminated

6.38mm

85

7

76

0.94

 

8.38mm

83

7

73

0.91

 

10.38mm

83

7

69

0.91

 

12.38mm

81

7

66

0.85

Grey Laminated

6.38mm

42

5

51

0.73

 

8.38mm

41

5

48

0.71

 

10.38mm

41

5

46

0.69

Bronze Laminated

6.38mm

51

5

52

0.74







Glass | The Sound Barrier
We will establish the degree of insulation required: simply subtract the interior noise level required from the exterior noise level. For example, a small street records up to 70dB while a bedroom requires 35dB: 70 - 35 = 35 ... a requirement of 35dB sound insulation in the window (and walls!).
Single Glass Weight

Thickness(mm)

Weight kg/m2

3

7.5

4

10

5

12.5

6

15

8

20

10

25

15

37.5

19

47.5

25

62.5


Laminated Glass


Normal Thickness (mm)

Average STL 125-4000 Hz (dB)

STC Rating (Glass)

% Perceived Sound Reduction

6.38*

29

34

40

8.38

33

35

45

10.38

35

36

50

12.38

36

39

57

8.76 PVB Acoustic

34

37

52

7 Acoustic**

34

37

52

9 Acoustic**

36

38

56

11 Acoustic**

36

39

57

17 Acoustic**

40

42

65



Annealed Glass


Normal Thickness (mm)

Average STL 125-4000 Hz (dB)

STC Rating (Glass)

% Perceived Sound Reduction

4

25

28

10

6

27

31

25

10

30

42

65

Glass Blocks 190x190x80

40

42

65



North Canterbury Glass Heat Loss
The Numbers Have It
In a typical single-glazed South Island window, heat loss is measured at a U value of 6.2.
With Glass Tech double glazing the heat loss is more than halved to 2.9.
Take a double glazed unit with standard glass, fill it with Argon gas, and you reduce the reading to 2.6.
Now consider additional benefits. Use Low E glass for double glazing and the heat loss drops all the way to 1.91; with Argon gas filling inside the Low E panes the heat loss is a staggering 1.61 U value.