Glass
Architectural Envelope Experts
Table of Contents Company Introduction Mission and Vision
1
Glass Division
2-4
History of Glass Making
5-6
Introduction to Heat-Treated Glass
7- 9
Summary of Cladtech International Fully Tempered (FT) Glass
10
Cladtech International Heat Strengthened (HS) Glass
11
Heat Soak Testing
12-13
Aesthetics: Distortion and Colour Impressions
14-16
Cladtech International Sealed Insulated Glass Units
17-19
CTI – LAM Laminated Architectural Glass
20-26
Spandrel Glazing
27-29
Compliances and Standards
30-31
Performance Definitions
32-34
Glass Interior
35
Glass Workflow & Glass Machinery
36
Glass Projects
37
COMPANY INTRODUCTION
Cladtech International is the region’s leading building envelope specialist. Backed by Al Rajhi Holding, a distinguished building solutions firm, we strive to provide our clients with comprehensive answers to their needs. Our vertically integrated business structure, including design, development and processing capabilities, allows us to meet all your construction requirements. The Aluminium, Metals, Cladding and Glass divisions offer a full range of services including the very best in customer care. No project is beyond our capacity and we can respond to any challenge. The company’s skilled craftsmen are capable of producing more than 600 bespoke, unitised wall panels per day to the highest standard of quality. Using the latest technologies and techniques, they ensure that Cladtech products continue to enjoy a reputation for excellence. Line managers and quality control officials carefully check every step of the production process, making certain your products arrive in perfect condition. Installation professionals are available to assemble them into a customised whole. Expert teams of engineers and consultants can enhance your project with unique integrated solutions through value assessments and site management. Competitive pricing and built-in cost savings will ensure the success of your venture in both the short and long term. Cladtech. We are the solution.
GLASS FACTORY
MISSION AND VISION
MISSION Our mission is to provide superior solutions for Architectural Curtain Walls and Metal Works through Research and Development, Innovative Production Technology, State-of-the-Art equipment and highly motivated employees, thereby sustaining our profits and creating long term value for our investors, business partners and employees.
VISION Our vision is to become a regional leader in modern faรงade engineering, promote energy efficient and environment friendly faรงade construction, whilst achieving added value to our customers and society.
1
GLASS DIVISION
The area designated for glass processing is approximately 11.700 m2. The plant is equipped with well advanced and automated machinery for almost all glass processing requirements. All processes are, in addition, computer controlled to guarantee high efficiency and quality and reduce handling of the glass to a minimum level.
The equipment available includes the following:
DESCRIPTION MAX. CAPACITY
• Cutting line
6,000 mm x 3,210 mm
• Automatic first arris
2,500 mm x 4,500 mm
• Tempering line
2,600 mm x 4,800 mm
• Laminating line
2,600 mm x 4,500 mm
• Heat Soak Testing Oven
3,000 mm x 5,000 mm
• Double glazing line
2,500 mm x 4,500 mm
• Integrated double edger (drilling and washing)
2,500 mm x 5,000 mm
• Gemy 9C (for polishing)
2,000 mm x 3,000 mm
• V+ 1250 (For horizontal drilling)
2,000 mm x 3,000 mm
• SB10 (for round polish)
(Max 2,000 mm x 3,000 mm)
Each machine is equipped with automatic handling devices to maintain the highest quality. Production capacity of Insulated Glazed Units is up to 40,000 sqm per month. Tempering capacity is up to 90,000 sqm per month. The glass plant has a reverse osmosis water treatment plant which allows the re-utilization of 80% of the water, reducing daily consumption and providing quality water wash for high performance glass and, at the same time supporting the “environmentally friendly” philosophy of the Company.
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GLASS MACHINERY
FIRST ARRISING Automatic arrising of rectangles and shapes with straight edges. Cup wheel technology for best arrising quality at low operating costs. No contact with coated surface of low-E glass. Wide application in tempered glass, laminated glass, and insulating glass manufacturing.
TEMPERING LINE The UGC heating system incorporates a fast responding open coil heater design. Individual turbocharger units located on the outside of the heating chamber re-circulate oven air and provides individual convention control for both glass surfaces, as the radiant heating system deposits heat according to measured pattern. Glass is heated very quickly but with a level of control that provides exceptional glass quality.
HEAT SOAK TESTING During the primary glass manufacturing process with the float method some nickel sulphide inclusions can occur in the glass. Variations in temperature increase the possibility of a spontaneous breaking of the pane after tempering when nickel sulphide is present thus causing potential damage to people and property. In order to reduce the risk of spontaneous breakage, the tempered glass should undergo the Heat Soak Test process. The glass is maintained at a 290ËšC temperature for a fixed period in order to accelerate the development of NiS inclusions during the test and cause breakage prior to delivery and installation.
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3
GLASS MACHINERY
CUTTING-LINE The glass cutting table is a high precision, high speed, low noise, batch production machine used for cutting straight and random shaped lines on flat glass. The CAD-CAM software, with its powerful shape compiling feature and optimization program, allows you to design your desired shapes easily and quickly. The high-grade servomotors and high-precision transmission modules are used to increase the quality
EDGE – WORKING LINES
of glass shape.
Providing consistent quality and high productivity.
INSULATING GLASS High-tech and most advanced technology for insulated glass. Capacity approx. 1500 sqm per day.
LAMINATING LINE Quality architectural laminated glass machine. Provides high quality and durable laminated and multi-laminated glass with high productivity.
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HISTORY OF GLASS - MAKING
The technology of glass-making goes back a long way to ancient Egypt, Phoenicia and Mesopotamia and has developed to become one of the fundamental contributors to civilised life as we know it today.
Polychrome glass vase, about 5 inch long in the form of a fish. Eighteenth Dynasty, from Tel-el-Amarna, Egypt.
The manufacture of window glass is a thousand years old dating from earliest Gothic cathedrals and has evolved from a hand-made material to one which can be mass-produced on a prodigious scale.
Contemporary architectural design demonstrates an on-going love affair with glass which provides transparency, daylight and a view of the world beyond pane. Glass protects us from the effects of short-term changes in the weather as well as the longer-term changes in the climate itself. Glass is a basic element of modern life and its potential is being constantly expanded by progressive architects and structural engineers. The limits of imagination in glass design and function have not yet been reached.
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5
The “Crown” process up to 1850 Surfaces not flat and parallel.
The “Cylinder” process up to 1910. Surfaces not flat and parallel
The “Drawn Sheet” process 1910 - 1970. Surfaces not flat and parallel.
The “Polished Plate” process 1850 - 1965. Both surfaces flat and parallel. No distortion. Intensive machining and labour inputs.
The “Float” Process remains virtually unchanged in principle since 1962. Surfaces flat and parallel. Natural Physical process. Minimal Labour. No machining.
When correctly installed in suitable frames, glass is one of the most durable of all building materials and, if unbroken, will go on to perform it’s protective role indefinitely. Cladtech International Glass are proud to make a valuable contribution to this on-going story.
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WHAT IS GLASS? COMPOSITION OF COMMERCIAL QUALITY WINDOW GLASS SODA-LIME GLASS
ORIGIN
DESCRIPTION
%
Silica(Si)
72
Limestone(CaCO3)
9
Dolomite (MgCO3)
4
Others
1
Manufactured Material
Soda Ash(Na2O)
14
By-Product Material
Clean Scrap (Cullet)
up to 20% by Volume
MINED OR QUARRIED MATERIALS
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7
INTRODUCTION TO HEAT-TREATED GLASS
Primary float glass, as manufactured, is a glass which is totally free
Briefly, the glass is heated to approximately 700˚C and is then
from stress which is known as “ANNEALED” condition.
force-cooled to create surface and edge compression in the glass. It is by controlling the rate of cooling that glass becomes
This allows it to be easily cut, drilled and edge-worked. However,
heat strengthened or fully tempered.
annealed glass cannot be used as a structural material and has extremely limited resistance to high wind-load, dead-load or to
To produce FT glass, the cooling is done very rapidly to induce
severe solar exposure. Furthermore, when broken, annealed
high surface compression in the glass. To produce HS glass, the
glass is a lethal material which can cause severe or fatal injury.
cooling process is slower and the resultant compression in the
Question: how can these limitations be overcome? Answer: by
surfaces is much less then FT glass.
heat-treatment in a modern horizontal roller furnace to induce additional properties into the annealed glass which will make
Because of the compressive stresses in the surfaces, HS glass is
it suitable for use in contemporary design including structural
approximately x2 stronger than annealed glass, and FT glass is x
silicone curtain wall systems and all forms of bolted frameless
4-5 stronger than annealed glass of the same thickness.
glazing. How Is This Done? Except for this increase in mechanical strength, all other properties
IMPACT BEHAVIOUR OF ANNEALED GLASS
typical break-pattern
of the glass remain unchanged. The most dramatic and important difference between HS and FT glass is in the post-breakage characteristics of the two products, as defined by the break-pattern.
face 1 2
If HS glass should break, the pieces will be relatively large and tend to remain in the glazing system until removed for replacement.
When loaded, in any circumstance, annealed glass will deflect
On the other hand, FT glass will shatter into innumerable small,
causing the face # 1 to develop a level of compressive stress
roughly cubical fragments which do not have sharp edges and are
while face # 2 is now in tension. As the load increases, the tensile
therefore “NON-INJURIOUS”.
stress in face # 2 also increases. Since glass is very strong in compression, but weak in tension, the face # 2 surface will soon
HS glass is not a safety glazing material, when safety glass is
reach it’s tensile stress limit and the glass will break. All stress
required to meet safety codes, A certified glazing material such as
forces will be relieved and the result is a potentially dangerous
fully tempered or laminated glass must be used.
fragmentation. Annealed glass cannot therefore be used for frameless glazing and is restricted for use only in areas which have no legal requirement for safety glass.
HOW CAN THIS SITUATION BE RESOLVED TO ALLOW SAFE GLAZING DESIGN? HEAT-TREATED GLASS (HS) AND (FT). Heat-Treated Glass products, whether heat strengthened (HS) or fully tempered (FT) are produced in a very similar fashion using the same kind of horizontal roller furnace employed by CLADTECH INTERNATIONAL.
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SUMMARY OF CLADTECH INTERNATIONAL FULLY TEMPERED (FT) GLASS
CLADTECH INTERNATIONAL FULLY TEMPERED (FT) GLASS FT glass is produced in a horizontal roller furnace in which the glass is heated to around 700 ˚C at which temperature it is red-hot and in a plastic condition. It is then rapidly cooled (quenched) by a force of cold air which causes all the outer surfaces (including the edges) to contract, thus creating a total “envelope” of compressive stress in face 1 and 2. However this rapid quenching of the surfaces is not immediately conducted to the centre of the glass which remains in a temporary state of expansion but then cools, after a short delay, to a greater degree of contraction than the surface. As a result, the centre zone of the glass is now placed in tension entirely within the compression envelope thus creating a perfect balance of forces. Clearly, if the FT glass is now subjected to a load, the compressive stress in face # 2 will allow the glass to absorb a much greater force without breaking and, on removal of the force, the glass will return to its original flat condition.
IMPACT BEHAVIOUR OF FT GLASS
Breaking of FT glass will occur when the deflection exceeds the capacity of the compressive envelope to resist the tensile force, or if the glass is impacted by a hard material which penetrates through the outer compressive zone to reach the tensile zone. The sudden release of energy stored in the tensile zone of the FT glass will cause total disintegration of the pane into small, fragments which are non-injurious. This important feature of FT glass means that it is considered by all major International standards to be a “TRUE SAFETY GLASS” for use in all glazing situations where impact resistance and thermal safety are required.
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9
SUMMARY OF CLADTECH INTERNATIONAL FULLY TEMPERED (FT) GLASS
PROPERTIES
SAFE GLAZING SIZE
– Is 4 – 5 times stronger than annealed glass of the same
The sizes shown below refer to manufacturing capacity
thickness
lamitations. The actual “Safe glazing size” will depend on design
– Has greater resistance to thermally-induced stress than heat
wind-load, dead load, whether single or double glazed, lamination
strengthened or annealed glass
and whether combined with annealed or heat strengthened glass
– Typically breaks into small particles which can be handled
in double glazing.
safely. – Suitable for use as a safety glass as defined by
For confirmation of “safe glazing sizes” please contact the
American Standard
ANSI Z-97.1 1984
Technical Sales Department at Cladtech International.
British Standard
BS 6262 Part A 2005
European Standard
EN 12600 2002
– Manufacturing conforms to American Standard ASTM C 1048 – 4
APPLICATIONS – All types of clear, tinted, pyrolitic-coated and post temperable sputter- coated glass are available in FT condition – FT glass can be used in any window or curtainwall framing system – FT glass is a structural glass which can be used for frameless glass facades, frameless glass doors, structural glass balustrades and many types of furniture – FT glass can be laminated with a suitable number of PVB interlayers – FT glass can be produced with silk-screen ceramic frit designs – FT glass cannot be cut or drilled after tempering and any posttempering operations such as edge-grinding, cutting, sandblasting may cause sudden, or premature failure.
AVAILABILITY
PRODUCT
CLEAR
TINTED
PYROLITIC
OR
POST TEMPERABLE SPUTTER COATED
T
4
6
FULLY TEMPERED 8
mm
10 12 15
Max 2600 x 4800 Min 300 x 300 T
6
Max
8 10 2400 x 3660
Min 300 x 300 T
6 8
Max
2400 x 3660
Min 300 x 300
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CLADTECH INTERNATIONAL HEAT STRENGTHENED (HS) GLASS
Throughout the Middle East Region, Architects and Engineers
SAFE GLAZING SIZE
have turned substantially towards the use of the HS glass for
The sizes shown below refer to manufacturing capacity limitations.
use in facades and windows where full impact-safety is not a
The actual “safe glazing size” will depend on design wind-load,
requirement. The absence of risk from spontaneous breakage, the
dead-load, whether single or double glazed, lamination and
better retention in the glazing system (if broken) and the improved
whether combined with annealed or fully tempered glass in double
surface quality, make HS glass the first product-of-choice for the
glazing.
majority of non-structural glazing situations. For confirmation of “Safe Glazing Sizes”, please contact the Cladtech International offers HS glass for a wide variety of
Technical Sales Department at Cladtech International.
applications requiring sufficient strength to resist stresses caused by absorption of solar energy and also to resist the forces of deflection under wind-load, dead-load etc. Due to its lower surface compression stress level, HS glass is unlikely to break spontaneously even if nickel sulphide stones are present in the tensile zone of the glass. Cladtech International strongly recommends the use of HS glass except for areas which are covered by mandatory safety codes.
Typical
Break-pattern
AVAILABILITY
PRODUCT
T
HEAT STRENGTHENED
4
6
8
CLEAR
Max
2600 x 4800
Min
300 x 300
T
mm
10
6 8
TINTED
Max
2400 x 3660
Min
300 x 300
PYROLITIC
OR
Max
2400 x 3660
POST TEMPERABLE SPUTTER COATED
Min
300 x 300
T
6
8
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11
HEAT SOAK TESTING
C L A D T E C H I N T E R N AT I O N A L H E AT S O A K TESTING (HST ) OF FT GLASS
Inclusion (c) is located within the tensile zone where it will commence to undergo changes to its crystalline structure, causing it to expand. Ultimately, after a period of time, which may be from
In its original state, float glass is produced as a primary raw
6-36 months after production, the expansion of the inclusion,
material in the form of large stock sheets which are intended for
although only from 2-4% in volume, can result in internal stress up
downstream processing to create the finished glass product as
to 500,000 psi which will cause “Spontaneous Breakage” through
installed.
total release of the latent energy contained in the tensile zone.
The float glass process ensures that the glass is cooled gradually
DISTRIBUTION OF NiS STONES IN HS GLASS
to ensure a stress-free condition which is described as annealed glass. This process of annealing allows the glass to be cut, edge-worked and drilled safely and accurately without risk of uncontrolled breakage. Cladtech International purchases its raw float glass requirements from reputable manufacturers which conform to best international standards including American Standard ASTM C 1036 in terms of surface flatness, surface quality and minimal internal impurities, bubbles and seeds within the body of the glass. Although float glass manufacturers take extreme precautions to
From the same random distribution, the critical inclusion (c) is not
ensure maximum purity of the raw materials, it is possible from
affected by the weaker forces of the small tensile zone and it will
time-to-time, for nickel sulphide (NiS) stones (which are invisible
therefore remain dormant indefinitely. HS glass has minimal risk of
to the human eye and also to electronic QC procedures) to occur
spontaneous breakage due to presence of inclusions (including
in the glass. Their extremely small size, typically from 0.076-
nickel sulphide) in the raw float glass substrate.
0.38mm, means that they are undetected by all practical detection methods, and so they may be present, randomly, in the float pane
Note:
which has been prepared for tempering.
On a world-wide basis, FT glass is not warranted against spontaneous breakage due to NiS or other impurities, and
DISTRIBUTION OF NiS STONES IN FT GLASS
replacement glass will be supplied at Owner’s expense.
HEAT SOAK TESTING Is not a guarantee that the FT glass will not fail at a future date, but Cladtech International advises its Clients to take the option of HST as an assurance of minimum risk for all glazed areas which may present difficult and costly access (out of proportion to the cost of the glass itself) when replacing glass which has experienced spontaneous breakage. From this random distribution of inclusions in the FT glass pane,
At buyer’s discretion the FT glass supplied by Cladtech International
it can be seen that (a) and (b) are located within the compression
maybe subject to partial, or random, Heat Soak Testing, or may
envelope where they will remain dormant indefinitely.
be 100% tested. Note: Cost of HST is determined by the thickness of the glass which affects the cycle-time in the HST oven.
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HEAT SOAK TESTING
Note:
AVAILABILITY
Spontaneous breakage may not always be due to Nickel Sulphide
Cladtech International has installed HST facilities to conduct Heat
inclusions, and can also occur as a result at edge-damage, surface
Soak Testing in accordance with European Standard EN 14179 in
scratches, glass-to-metal-contact, all of which can contribute to
which the “Holding Time” is 2 hours at 290 ˚C.
weakness and premature failure of the glass. HST OVEN-CAPACITY: UP TO 5000 x 3000 mm
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COMPARISON OF FULLY TEMPERED AND HEAT-STRENGTHENED GLASS CHARACTERISTICS Surface Compression Stress
FT 80N/mm2 to 150N/mm2 But ≥ 100N/mm2 for safety glazing quality
HS 25N/mm2 to 52N/mm2
≥ 4 times that of annealed glass. Mechanical Strength
≥ 2 times that of annealed glass. Not suitable for bolted fixings
≥ 6 times that of annealed glass. Resistance to Thermal Stress
≥ 2 times that of annealed glass.
can used with bolted fixings
Sufficient for most glazing application
300 C Max Operational Temperature
150OC
Breaks into small, relatively harmless fragments. Fracture Characteristics For safety glazing needs ≥ 40 particles in 50mm
Fracture similar to annealed glass. Should not be regarded as a safety glass.
O
square when tested to ASTM C 1048
Some optical distortion may be expected within limits set by ASTM C 1048
Can be less than for tempered glass.
Some bow may be expected within limits set by Overall Bow
Can be less than for tempered glass.
Thickness
4mm to 19mm
4mm to 10mm
Nickel Sulphide Inclusions
A very small proportion of panels may contain critical Nickel Sulphide (NiS) inclusions. Most of these can be eliminated by Heat Soak Testing.
Not generally regarded as a source of fracture. Heat Soak Testing not applicable.
Optical Distortion
ASTM C 1048
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13
AESTHETIC ASPECTS
DISTORTION AND COLOUR IMPRESSIONS
– Distortion is only visible when an image is reflected. Depending
Prior to Heat-Treatment, annealed float glass has surfaces which
on the proximity of the observer to the glazed surface, the
are flat and parallel giving it almost perfect optical qualities when
amount of distortion will vary. When standing close to the glass,
viewed at any angle of incidence.
the degree of distortion is very small, but increases as the observer moves away from the building.
Heat-Treatment of architectural flat glass is done in a horizontal roller type furnace at up to 700 ˚C. At this temperature, the glass
– Colour is always more intense when close to the glass, and fades with increasing distance.
is red-hot and in a plastic condition. To prevent the soft glass from sagging between the supporting rollers, the roller bed oscillates
STRAIN PATTERNS
forwards and backwards during the entire heating and quenching
Slight variations of stress across the surface of heat-treated glass
cycle. Nevertheless, in spite of this constant movement, there will
may become visible to the eye due to polarization of light at certain
always be a tendency for some minor sagging to occur and this
times of day, especially near sundown when the glass is not in the
flatness-irregularity will be permanently manifested in the HS or
sun. Strain patterns can be noticed in all heat-treated glass types,
FT glass product as Roller Wave Distortion. This typical feature of
but are more noticeable in tinted glass with reflective coatings.
Heat-Treated glass is an inherent characteristic of the product and
They are, however, present in all Heat-Treated glass types and are
is not a quality-problem.
not considered defects.
At Cladtech International, HS and FT glass are produced within the flatness tolerances of the current version of American Standard
MOCK-UP SAMPLES
ASTM C. 1048.
Distortion, colour and reflectance of Cladtech International HeatTreated glass products are important design considerations that
Visible distortion can be minimized by ensuring that the Heat-
architects and owners should evaluate in a full size mock-up
Treated glass is manufactured and installed with the characteristic
erected on site (including a properly designed shadow-box) prior
roller-wave parallel to the W-Dimension. All glass cutting-lists
to final selection of the desired glass.
from the Buyer must show W as the first dimension, and H as the second dimension.
ENVIRONMENTAL EFFECTS ON DISTORTION AND COLOUR IMPRESSIONS Distortion and colour can be affected by the following environmental factors: – The presence of a reflective and/or low-E coating which can exaggerate the roller-waves compared to clear or tinted (uncoated) glass. – Distortion can be accentuated in sealed insulated units due to changes in barometric pressure and changes in temperature acting on a fixed volume of air hermetically sealed between the two glass lites. – Accuracy of installation of framing system and correct tightness of fixing screws can have a significant effect on the planarity of the glass surfaces. Even small deviations of tolerance in the installation of the frames can produce substantial visual distortion. – Distortion tends to become more visible when viewed from
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some distance away from the building.
14
AESTHETIC ASPECTS
COLOUR IMPRESSIONS
09.00
Cloudy Conditions
15.00
1800
Close-up
The combination of a mobile sun, a mobile observer, a dynamic sky as well as the tint/colour and reflectance of the glass itself provides a continually changing aspect with stunning and dramatic effect throughout the day, and every day.
DISTORTION
500 m
100 m
35 m
5 m
Colour and distortion will vary according to distance of observer from the façade
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15
GLASS FACTORY
16
CLADTECH INTERNATIONAL SEALED INSULATED GLASS UNITS
Cladtech International is equipped with the latest model Bystronic Robotic-Sealing line for the manufacture of dual-sealed insulated glass units. Through this extremely modern technology, the entire process of glass-washing, edge-deletion (where required for certain types of Low-E glass), positioning of the aluminium spacer-tube and application of primary and secondary sealants is done with great precision and efficiency. Depending on the daily combinations of glass thickness and dimensions, this superb equipment has a potential capacity of 40,000 sqm per month.
WHY DOUBLE GLAZING? Ambient heat transfer (outdoor-indoor) can occur via three mechanisms, Absorption, Conduction and Radiation. Because of its transparency, glass can allow potentially large amounts of conducted, as well as directly-transmitted, heat to enter a room-space. Glass is the weakest material in terms of heat-gain or heat-loss in buildings, depending on the climate. This gain or loss can be substantially reduced with the use of insulated double glass units. Insulated glass units create a dead (non-convective) airspace between two panes of glass, thus slowing down the rate of heat exchange between ambient warm and cold air-masses on either side of the unit. The reduction of heat-transfer through the glazing in modern building-design is of vital importance in minimizing the capital cost, and subsequent running cost, of heating or cooling (A/C) equipment over the entire life cycle of the building. Room interior comfort-levels are also significantly improved, in both summer and winter, through the use of insulated glass. Cladtech International insulated glass units are manufactured using the proven dual-seal principle in which two panes of glass are separated by a dehydrated airspace at ambient barometric pressure. The units conform to current American Standard ASTM E-2190
TYPICAL U-VALUES FOR GLASS
MAKE-UP(mm) U-VALUE (W/m2K)
6
SINGLE
6
6.50
24
DOUBLE
6 + 12 air + 6
3.30
28
DOUBLE
6 + 16 air + 6
3.10
24
DOUBLE
6 Solar control + 12 Air + 6
2.50
24
DOUBLE
6 Low-E + 12 Air + 6
1.70
28
DOUBLE
6 Low-E + 16 Air + 6
1.50
28
DOUBLE
6 Low-E Double Silver + 16 Air + 6
1.40
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T (mm) FORMAT
CLADTECH INTERNATIONAL SEALED INSULATED GLASS UNITS
COMPARISON OF THERMAL AND ACOUSTIC PERFORMANCE THERMAL
ACOUSTIC
OF SEALED UNITS ACCORDING TO AIRSPACE
2.20
Tranmission Loss (TL) dB
2.10
In addition to the thermal insulation benefits of sealed insulated
U- Value 2.00 W/m2 K
units, there is also the additional benefit of improved acoustic
1.90
insulation. However, whereas the optimum airspace for best
1.70
U-Value is 16mm, there is a continuous sound insulation benefit from every increase in the airspace.
1.40
8mm
12mm
16mm
20mm
Note: U-Values based on Low-E on surface # 2.
25mm
AIRSPACE
LT%
60
60
50
50
40
40
30
30
20
20
Typical spectrophotometric performance range obtained with
10
10
Cladtech International Glass sealed insulated units.
Standard Low - E #2
Multi-Functional Low - E #2
SPECTROPHOTOMETRIC CHARACTERISTICS SHGC
Solar Control
Typical 24mm insulated glass units (6+12+6m)
Dew Point ̊ C
CONDENSATION
Dew Point ̊ C
Risk of Condensation
Dew Point ̊ C
Sealed insulated units play a major role in the reduction of condensation in the typical Gulf environment by lowering the dewpoint of the outer glass surface when Relative Humidity (RH) levels are high and air-conditioning is still in use.
Single
Double (Un-Coated)
Double Low-E #2
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CLADTECH INTERNATIONAL SEALED INSULATED GLASS UNITS
AVAILABILITY
Air space (mm)
Normal Maximum size (mm)
6, 8, 10, 12, 16, 20
2500 x 4500
All CTI glass types can be incorporated in insulated glass units in FT, HS or AN (annealed) conditions.
FRAMING MATERIAL The efficacy of insulated double glazing is seriously affected by the quality and design of the framing system. Frame materials, such as steel or aluminum, are capable of transmitting excessive amounts of heat to the edges if insulated glass in hot weather. Similarly, it is possible for the frame to create a serious lowering of the temperature around the edges in cold weather. In each case, only the center of the glass will perform according to its true thermal resistance (U-Value) with serious effect on its efficiency and cost-benefit to owners and occupants. For this reason, it is strongly recommended that the metal framing systems should incorporate a thermal break in the design. Timber and UPVC frames offer better thermal resistance with minimum effect on the overall U-Value of the glass.
WARRANTY Cladtech International provides a 10 year Standard Product Warranty for all insulated Glass Units manufactured with standard continuous bendable spacers.
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CTI – LAM LAMINATED ARCHITECTURAL GLASS
MODERN ARCHITECTURAL DESIGN continues to
The principal benefits of Laminated glass are as follows:
depend with growing emphasis on the beauty and durability of glass to perform an increasing multitude of tasks. SAFETY
VERSATILE AND INDISPENSABLE, glass is used worldwide to enhance facades with brilliant colour, to illuminate interiors, and to protect occupants from the weather, from fire,
SECURITY
from noise, and from criminals. It keeps us warm, or cool, with optimum consumption of energy, but it has one fault – it is fragile and breaks easily and then no longer acts as a protective barrier. Throughout
the entire Gulf Region, there is an increasing
SOLAR control
awareness of the need for glazing systems which provide safety and protection to persons and property in danger from accidental impact or from vandalism, from robbery and, sometimes, from murder.
SOUND control
Laminated glass provides an answer to most of these problems and to meet these demands, CTI is proud to announce the
And the performance of LG can be varied by many combinations
opening of its new factory for the production of laminated glass
of glass and interlayer thickness.
using PVB interlayer material.
WHAT IS LAMINATED GLASS?
See Table 1
SAFETY for Availability
Laminated glass is formed by creating a sandwich of two of more sheets of glass bonded to each other under heat and pressure,
The safety of glazing in buildings is now a matter of universal
using a plastic interlayer of PVB (Poly Vinyl Butyral) which has
concern. Annealed CTI – LAM with 0.38mm up to multi layer
optical and light transmission properties almost equal to the glass
1.52mm Interlayer is a true safety glass for use in residential and
itself.
public buildings where any glazed opening is at risk from accidental human impact. When broken, CTI - LAM remains in the frame and
CTI – LAM
continues to perform safely, resisting penetration by the impacting
cannot be visually distinguished from standard clear glass when
object or person, until replacement glass can be installed. In areas
both are used in different locations on the same building elevation.
of risk, many countries have formulated Legislation based on Local, National and International Building Codes to make the use
CTI – LAM
of safety glass mandatory. CTI - LAM conforms to most building
is a durable, versatile, composite glazing material which answers
code requirements including CPSC CFR1201, ANSI Z97-1-1975
a wide variety of Architectural questions.
and BS-6206.Laminators, including Cladtech, regularly test their products to a swing-bag impact test. Note: Laminated glass is not a structural glass and therefore each laminated lite must be individually supported without bearing on its neighbour. Tempered glass, which can be used structurally, is not an effective security / safety glass since, when heavily impacted, it will disintegrate completely, leaving a void in the glazing.
▲ 20
CTI – LAM LAMINATED ARCHITECTURAL GLASS
See Table 2
SECURITY for Availability
Generally, a 2-ply laminated product, with 1.52mm PVB interlayer,
Robbery and violence are growing aspects of modern life and
under severe blast conditions.
will provide a high level of protection, with no glass fall-out, even
glazing systems have been designed to withstand smash-and -grab attacks on any premises which store or display valuable commodities.
For maximum resistance, both panes should be HS. In the case of double glazing, the outer pane should be monolothic (non-laminated) HS glass, and the inner Pane must be laminated
Anti-bandit glass This is an annealed glass laminate with a 1.52mm PVB interlayer and is sufficiently tough to resist penetration when attacked by bricks and sledge hammers. In most cases, burglars are deterred by the laminated glass and run away empty-handed to look for a easier target.
HS glass.
SECURITY
See Table 4 for Availability
Bullet Resisting Glass is composed of multi layers of glass and PVB which form an
Burglar resistant glass This is typically used for shop fronts, banks, museums ticket kiosks, control rooms etc., and any other type of buildings with security risk.
effective barrier to penetration by bullets from medium and high velocity weapons. Configuration of the glass and PVB depends on the type of ammunition, the weapon, the velocity of ammunition, and the firing distance. Bullet Resisting Glass is used principally
See Table 3 for Availability
SECURITY
Heavy duty laminated glass This is designed for use in areas where additional protection is
in areas where money is handled and where personal safety is paramount.
SOLAR
considered vital. A minimum of three glass sheets combined with multiple layers of PVB offers a high level of deterrence and prolonged resistance to violent attack.
Laminated glass may be designed to reduce solar energy transmission, to control glare and to screen out ultraviolet (UV)
SECURITY
or
In buildings subjected to extreme blast-forces, the majority of deaths and injuries are caused by broken glass, especially where the windows are fitted with annealed glass. Laminated glass, correctly installed in suitable framing systems, will mitigate, or totally prevent, the penetration of glass fragments into the building. However, whereas the velocity and impactforce of bullets can be calculated, blast-forces are much more unpredictable and can vary according to – Distance of glazing from the explosion – Height of glazing above the explosion
radiation. Transmitted solar heat is reduced by the use of CTILAM incorporating tinted or high performance reflective glass, coloured interlayers, or combinations of each which absorb part of the solar radiation in the UV, visible, and infra red ranges of the solar spectrum. Further enhancement of thermal insulation will be obtained when the CTI-LAM tinted heat absorbing or reflective glass are combined in an insulating unit. Note: Proper glazing design should take into account any thermal mechanical stress which might affect the glass . If the tinted or reflective laminate is a single lite, or is used to form the exterior lite of an insulated CTI-LAM glass unit, it may be necessary for the glass to be Heat Strengthened or Fully Tempered depending
– Weight of the explosive charge
▲
21
CTI – LAM LAMINATED ARCHITECTURAL GLASS
on the glass size, colour of the interlayer, solar absorptance and
Tight glazing of acoustic glass is critical in achieving optimum
the design wind load. However, if the laminated glass forms the
STC ratings. All window clearances must be thoroughly sealed
interior lite of an insulating unit, the lite may not require to be heat
and all openable frames must fit tightly against EPDM or neoprene
treated except when used in blast-resisting applications. CTI-LAM
gaskets on all sides. The slightest crack in any glazed opening will
is extremely durable and stable and continues to provide original
result in substantial transmission of outside noise and destroy the
levels of UV screening after many years of prolonged exposure to
value of the glass itself.
direct sunlight.
SOUND
or
In addition to being transparent to light and solar energy, glass has a relatively poor resistance to noise and windows are always the weak point in any façade, allowing the transmission of unwanted sound into the building. Laminated glass is highly effective in reducing noise transmission and can be used in standard window and curtain wall designs. Laminated glass (2 ply or 3 ply) reduces sound transmission over a wide frequency range depending on glass and PVB interlayer thickness. In addition, when used as one, or both, of the lites of an insulating glass unit, the sound transmission is reduced even more dramatically over a wider sound frequency range depending again on the glass, interlayer and airspace thickness. CTI – LAM in single glazing, or combined in an insulating unit gives optimum control of noise transmission over a very wide range of sound frequencies from 100 - 5000 Hz. Combinations of CTI – LAM glass, taken together, provide a better noise barrier than either monolithic or non-laminated insulating glass. With various configurations of glass and interlayer it is possible to achieve the desired Sound Transmission Class (STC) rating which is a means of comparing the acoustic performance of glass and other building materials. Acoustic CTI – LAM conforms to tests and procedures under ASTM E 90 and the STC ratings are derived from calculations according to ASTM E 413. This system of rating is used to quantify the sound isolation performance of walls, floors, ceilings, doors and windows including glass. The test results are expressed as a single STC number. The higher the STC rating, the better the sound isolation performance of the glazing.
■ 22
CTI – LAM LAMINATED ARCHITECTURAL GLASS
UV RADIATION PROTECTION
Thermal Breakage
Ultraviolet light is one of the most serious causes of fading in
Glass that absorbs solar radiation can break due to thermal stress. Thermal stress is proportional to the temperature differential between shaded and exposed areas, and the coefficient of thermal expansion of the glass.
goods and materials exposed to direct sunlight through glass. The cost of losses due to fading can be substantial. Laminated glass is virtually opaque to UV radiation which occurs in a waveband from 310-380 nm in the Solar Spectrum, whereas standard 6 mm clear float glass transmits 55% UV at 350 nm. As a further example UV radiation at 350 nm has a damage-potential 50 times greater than that of visible light at 500nm.
ULTRAVIOLET SCREENING PROPERTIES
THICKNESS OF PVB in
TOTAL UV RADIATION FILTRATION
6mm CTI-LAM GLASS.
(CUT-OFF AT 380nm)
0.38 mm
99% +
0.76 mm
99% +
1.14 mm
99% +
1.52 mm
99% +
6.00 mm. Clear Float Glass
55% at 350nm
Factors which accentuate a HOT center / COLD edge condition will tend to increase thermal stress. For example, shadows cast by building overhangs, surroundings structures, trees and shrubbery can create a variety of exterior shading patterns on the glass. As a result, varying degrees of thermal stress may be induced in the glass edges, sufficient sometimes to cause thermal breakage. The maximum thermal stress occurs when 25%, or less, of an individual glass lite is shaded and the shaded area includes more than 25% of the lite’s perimeter. Generally, horizontal, vertical and diagonal shading patterns are not as critical as shading which includes combinations of these shading patterns. Double diagonal shading creates a “V” pattern with the center of the “V” located at the center of glass edge, is generally the most critical shading pattern.
Results are for Clear PVB only. Pigmented PVB will have equal or greater screening performance. The data and information shown above are based on samples tested and are not guaranteed for all
The following diagram shows some typical shading patterns which can be created in a building. These are labeled “acceptable”, “marginal” and “harmful”. These drawings and designations can serve as a guide to the severity of thermal stresses created by various exterior shading patterns. If an unusual shading pattern is anticipated please contact Cladtech Technical Department to determine if heat strengthening (HS) or full tempering (FT) is required.
samples or applications. Note : Although UV radiation is the primary cause of fading, oxygen, moisture, pollution, elevated temperatures, visible light and normal wear will also contribute to interior product degradation. The UV radiation protection of PVB is also stable with time. All clear and tinted PVB interlayers have been shown to provide original levels of UV protection after tests equivalent to more than five years of exposure under full desert conditions.
INSTALLATION Anti-bandit, high security bullet-resisting and blast-resisting glass can perform at maximum efficiency only if installed into suitably designed framing at systems which are also able to withstand the forces transmitted to the glass. Full protection therefore depends on a combination of glass, frame and fixing-method in suitably engineered structural openings.
▲
23
Generally, laminated glass with varying absorptance, transmittance and reflective characteristics performs similarly to monolithic clear or tinted glass when exposed to the same incidence of direct sun strike. Where the solar intensity is severe, leading to high heat absorptance or the risk of harmful shading it will be necessary to use 1:14 (3x0.38mm) or 1.52mm PVB interlayer. This is due to the un-synchronized roller-wave distortion which occurs in all heat treated glass. The additional thickness of PVB helps to compensate for the voids and possible mismatches created by the HS or FT processing, and results in complete surface contract within the PVB.
GLASS MACHINERY
▲ 24
CTI-LAM LAMINATED ARCHITECTURAL GLASS AVAILABILITY TABLE 1
CTI - LAM TWO-PLY LAMINATED SAFETY GLASS
Nominal Composition
Approximate
Glass Thickness
nett weight kg./m2
Code Des. Glass mm. PVB mm. Glass mm.
Maximum Production Size mm.
Condition
6.5
33.1
3.0
0.38
3.0
3210 x 2250
15
ANN Only
7.0
33.2
3.0
0.76
3.0
3210 x 2250
15
ANN Only
8.5
44.1
4.0
0.38
4.0
2440 x 3660
20
ANN Only
9.0
44.2
4.0
0.76
4.0
2440 x 3660
20
ANN Only
10.5
64.1
6.0
0.38
4.0
2440 x 3660
25
ANN Only
11.0
64.2
6.0
0.76
4.0
2440 x 3660
25
ANN Only
12.5
66.1
6.0
0.38
6.0
2440 x 3660
30
ANN Only
13.0
66.2
6.0
0.76
6.0
2600 x 4500
30
ANN Only
Maximum production sizes should not be Notes: - Available also with one, or both lites of Heat Strengthened (HS) or Fully Tempered Glass (FT). assumed to be “safe” - When using combinations of HS or FT Glass it will be necessary to specify 66.3(1.14mm PVB) or glazing sizes. For advice 66.4 1.52mm PVB) lamination on “safe” glazing sizes, please consult CTI - Available with translucent (opac) PVB where privacy or glare control is required. Technical Dept.
TABLE 2
CTI - LAM TWO-PLY BURGLAR RESISTANT, ANTI-BANDIT LAMINATED GLASS
Nominal Composition Glass Code Maximum Thickness Des. Glass mm. PVB mm. Glass mm. Production Size mm.
Approximate nett weight kg./m2
Condition
7.5
33.4
3.0
1.52
3.0
3210 x 2550
15
ANN Only
9.5
44.4
4.0
1.52
4.0
2440 x 3660
20
ANN, HS
13.5
66.4
6.0
1.52
6.0
2600 x 4500
30
ANN, HS, FT
Notes: - As above, Table 1
▲
25
CTI-LAM LAMINATED ARCHITECTURAL GLASS
TABLE 3
CTI - LAM MULTI-PLY HEAVY DUTY LAMINATED GLASS
Nominal Composition Glass mm. Maximum Thickness Des. Glass mm. PVB mm. Production Size mm.
Approximate nett weight kg./m2
Condition
10.0 mm
3-PLY
3 x 3.0
2 x 0.38
2000 x 2500
25
ANN Only
13.0 mm
3-PLY
1 x 6.0 2 x 3.0
2 x 0.38
2000 x 2500
32.5
ANN Only
16.0 mm
3-PLY
2 x 6.0 1 x 3.0
2 x 0.38
2400 x 3000
40
ANN Only
19.0 mm
3-PLY
3 x 6.0
3 x 0.38
2600 x 3600
47.5
ANN, HS, FT
22.0 mm
4-PLY
3 x 6.0 1 x 3.0
3 x 0.76
2400 x 3000
55
ANN, HS, FT
25.0 mm
4-PLY
4 x 6.0
3 x 0.76
2600 x 3600
62.5
ANN, HS, FT
Notes: - As above, Table 1
Will require additional PVB when using HS or FT glass.
TABLE 4
CTI - LAM BULLET RESISTING LAMINATED GLASS
Nominal Glass Safety Glazing Approval (1) Thickness mm.
Production Size mm. Approximate Maximum kg./m2 nett weight
26.0mm
Medium Power Small Arms
2000 x 3000
70
36.0mm
High Power Small Arms (.357 Magnum revolver)
1500 x 3500
97
52.0mm
High Power Small Arms (.44 Magnum revolver)
1200 x 3000
126
75.0mm
High Power Rifle Armour Piercing (AP)
1200 x 2400
186
Notes: As above, Table 1.
â– 26
SPANDREL GLAZING
The term “SPANDREL” is used to describe a material, frequently glass, which covers an area of a curtainwall façade occurring in front of a structural beam or column including any services void between the underside of the beam and the false ceiling. It may also refer to the area of the curtain wall in front of a parapet-wall where it is desirable to continue the visual effect of a total glass façade. When using glass as a spandrel material, its appearance and aesthetic qualities are closely related to the Visible Light Transmittance (VLT) and the external reflectance (LRout) of the vision glazing product. Various technical solutions are available
VLT=10%
to create glazed spandrels which are either MATCHING,
HARMONIZING
HARMONIZING or CONTRASTING.
Harmonizing spandrel glazing is obtained when the VLT of the vision glazing is ⩾14%, but especially ⩾20 %. Spandrel glass can
MATCHING
be single or double glazed and installation details are similar to
Matching of vision and spandrel glazing can be achieved when the VLT of the vision pane is
⩽14%
and the spandrel glass is
composed of the same glass which comprises the Outer Pane of
those shown in the diagram. With progressive increase in VLT, the spandrel colour will display progressively darker tone of colour compared to the adjacent vision panel.
the vision glass. Higher VLT also means higher transparency which increases Matching spandrel glass types can be double glazed equivalent to
the degree of “Read-Through” (Visibility) of structural elements,
the vision pane, or can be single glazed, usually high performance
installation details, curtains and luminaires. For this reason, a
Solar Control Glass with a durable sputter-coated or pyrolitic
well-designed shadow-box / back-pan detail is essential in order
coating on surface # 2.
to achieve a satisfactory visual and aesthetic appearance of the spandrel glazing. Nevertheless due to the creation of darker (SP)
In each case, the glass spandrel (SG or DG) will be installed
and lighter (VP) tones, there will be a “ STRIPPING” effect which is
in front of an insulated folded metal “Back-Pan” containing a
typical of harmonizing spandrel glass types.
suitable insulation material to prevent transmission of conducted solar energy into the concrete structure itself. A black or dark
NOTE: From 14-20% VLT, the colour-uniformity change is
grey polyester powder coat finish on face # 1 of the back-pan
marginal, depending on the tint and external reflectance of the
will provide perfect shadow-box conditions to ensure complete
vision pane and its harmonizing spandrel.
uniformity between the spandrel and its adjacent vision panel. fire stop
VLT=17%
FFL
services void
insulated metal back pan spandrel (SG) vision pane (DG)
▲
27
SPANDREL GLAZING
STRUCTURAL SILICONE GLAZING Glass shall not be used as a load- bearing element, and all glasspanes must be installed independently from their neighbours. This applies equally to structural silicone curtain wall systems and bolted glass systems. In general, adequate tolerance must be provided between adjacent panels. Glass-to-Metal contact is strictly prohibited. Support-framing, spider-connections etc must be of sufficient strength to absorb all loads resulting from design wind-load, thermal expansion and building movements. Centreof-Glass-Deflection (COGD) should (in most cases) be limited to 19 mm Edge-deflection must be limited to 1/175 of the longest dimension. Cladtech International Glass can supply silicone-sealed IG units and single (or double ) spandrel glass for all structural silicone framing systems including those which employ “Schuco” or modified Schuco structural IG spacers or for any curtain wall system which uses U-inserts in the IG perimeter seal.
VLT=37%
CONTRASTING Contrasting spandrel glazing will occur when the VLT of the vision glazing is 50%. At this level of VLT, even the back-pan itself will be
1 Schuco
2 Modified Schuco
3 U-insert
visible and it will therefore be necessary to apply a 100% coverage
Due to compatibility limitations of the silicone bonding materials
of ceramic paint, usually white, grey of black, on face #2 of an
with certain types of glass or insulated unit secondary sealant,
un-coated single glass, or on face # 4 of a Low-E IG unit. Acid-
purchasers must seek verification and approval of any structural
etching, sandblasting or the use of translucent PVB, (laminated
system from the silicone manufacturer and confirm that the
glass) can also achieve satisfactory results.
Structural Glazing Depth (SGD) of the IG sealant is sufficient to withstand all the loading conditions.
SGD (Nominally 6.4 mm) W
EDGE DELETION Higher VLT solar control or Low-E glass types may show varying degree of “Edge-Read” when double glazed, and designers should note that the majority of Low-E glass types have o be “Edge-Deleted” before being manufactured into sealed insulated glass units. This edge-deletion results in “Read-through” of the IG sealants as well as the structural bonding sealant in certain types
VLT=47%
of structural curtain wall systems, particularly in openable frames
■
where stepped IG units are required. 28
GLASS FACTORY
29
COMPLIANCES & STANDARDS
All CTI products comply with major international standards
that glass products are appropriate for any particular application
and codes of practice. Revisions of applicable standards and
and so comply with all relevant construction, building safety and
codes will be acknowledged by CTI through adjustments to
other codes of legislation.
the formulation and manufacturing process of their products. However, specifications and other technical data are based on
CTI are currently certified according to ISO OHSAS 18001, 2007
information available at the time of publication and are subject to
and ISO 9001.2008.
change without notice.
CTI conform to the following European and American Standards.
Any Third Party testing required to verify the performance or specification of a product, where such is considered to exceed
Note: These standards are for compliance only but may in some
or vary from the performance or specifications given by the
cases, be certifiable. CTI have adopted these standards as reliable,
manufacturer, shall be at the purchaser’s expense.
internationally-recognized guides for the production of commercial
It is the purchaser’s responsibility to ensure that the information
quality architectural glass. No certificates are provided, but CTI can
on which they are basing their buying decision is correct and
issue compliance-statements to confirm that their manufacturing
they should seek confirmation from CTI that the specification
processes meet, and / or exceed, the requirements laid down by
(technical, performance and any other data), are the most up-to-
these standards.
date before placing their order. Furthermore, they should ensure
Conformance standards followed by CTI Glass
AMERICAN STANDARD
ASTM C1036 - 6
BS/EN Standard EN
572-9
DESCRIPTION
2004
BS / EN 12150 -2
2004 FT
Standard specification for HS and FT coated and
ASTM C1048 – 4
BS / EN 1863 -2 EN 14179 -1
2004 HS 200 HST
ASTM C1172 – 9
EN
1449
2005
Standard Specification for Laminated Architectural flat glass
ASTM C1369 – 7
Secondary edge sealants for structurally glazed IG units
ASTM C1376 – 10
BS / EN 1096 -4
2004
Standard Specification for pyrolitic and vacuum deposition coatings on flat glass
ASTM E2188 – 2 E2189 – 2
EN EN
1279 -2 1279 -1
2002 2004
ong-term testing of sealed insulated glass units L including generalities, dimensional tolerances and rules for the system description
ANSI Z-97
BS EN BS
6206 1981 12600 2002 6262 part4 2005
ANSI E 1300-9
BS / CP 152 BS 6180 -99
Standard specification for glass
un-coated glass Heat Soak Test Method
Pendulum impact test method and classification for flat safety glass Glazing for building safety related to human impact
etermination of load-resistance of glass in buildings D Glazed barriers in, and around, buildings
▲ 30
COMPLIANCES & STANDARDS
INSULATED UNITS All dual-seal insulated glass units are produced with black lacquered and mill finish aluminum bendable aluminum spacer tubes. Other finishes must be specified. Stepped units can be produced with 1 to 4 sides stepped. Standard sealants in use are : - Encapsulated glazing
:
2-part poly-urethane
- Structural glazing
:
2-part structural silicone
All primary sealant is composed of PolysolButylene (P.I.B) Maximum manufacturing limitation : 2500 x 4500mm (subject to substrate availability)
HEAT TREATMENT All glass-types are available in Heat-Strengthened (type ‘HS’) and Fully Tempered (type (‘FT’) condition. HS and FT processing is done in accordance with American Standard ASTM C – 1048 – 04. Manufacturing limitations of heat treated glass (subject to substrate availability) Dimensional (mm): 2600 x 4800 (Max) 300 x 300mm (Min)
HS
4
6
8
10
FT
4
6
8
10
Thickness (mm):
12
15
19
EDGE DELETION All soft-coated low-E glass supplied by all glass manufacturers require edge deletion to provide an uncoated surface where primary and secondary IGU sealants are in contact with the glass. As result, in all structural silicone, or butt-jointed applications, the IGU sealants will be visible from the exterior. Sputter - coated solar control glass types and pyrolitic coated glass types do not require edge-deletion.
EDGE-WORKS In order to avoid external edge reflection in structural silicone curtain wall applications, CTI recommends flat ground (FG) edges for all heat-treated coated glass. This must be specified on the order, drawings and cuttings lists. In the absence of this information, all heat-treated glass will be documented and processed with standard arised edges.
■
31
DEFINITIONS
Definition of light and energy terms for spectrophotmetric
ENERGY REFLECTION - ER%
and thermal insulation criteria
Energy Reflection is the percentage of the solar energy reflected away from the outer surface of the glass, compared to the total incident solar energy. ENERGY ABSORPTION - EA% Energy Absorption is the percentage of the solar energy absorbed by the glass body, compared to the total incident solar energy. ENERGY TRANSMISSION - ET% Energy Transmission is the percentage of the solar energy transmitted through the glass, compared to the total incident solar energy. SOLAR HEAT GAIN COEFFICIENT - SHGC This is the total energy transfer which takes place by a combination
VISIBLE LIGHT Visible light represents 53% of the solar spectrum and has a
of direct transmission and re-radiation when a glass exposed to the
wavelength of 380 to 780 nanometers. Light passing through
sun under boundary conditions laid down in American Standard
the eye causes the brain to experience the sensation of light
ASTM G-173. These conditions fundamentally comprise:
within these wavelengths. The measurement of daylight has been
– Air-Mass (AM)
= 1.5
standardized by the International Lighting Committee using the
– Solar Altitude
= 42 ̊
D65 Illuminant described in the ISO DP9050.
– Glass Inclination
= 37 ̊ towards the sun in cloudless conditions
The SHGC of 3mm clear glass is 87% (0.87). All other glass types LIGHT TRANSMISSION - LT%
will therefore have SHGC < 0.87 .
Light Transmission is the percentage of visible light transmitted
The lower SHGC, the better the solar resistance of the product.
through the glass, compared to the total visible light that reaches SOLAR FACTOR - SF (equivalent to g-Value EN 410)
the glass at 90 ̊ angle.
This is fundamentally the same as SHGC in principle, although LIGHT REFLECTION - LR%
there may be slight differences in the boundary conditions, which
Light Reflection is the percentage of visible light reflected away
typically give SF/g-Values slightly higher than American SHCC
from the surface of the glass, compared to the total visible light
values.
that reaches the glass at 90 ̊ angle in accordance with the criteria SHADING COEFFICIENT - SC
contained in the ISO 9050-1990 Standard.
The Shading Coefficient is the ratio of the total energy transferred through a specific glass compared to the Solar Heat entering
SOLAR ENERGY Solar energy is the total energy made up of all three wave length
a room through 3mm clear float glass, which is the thinnest
bands of energy within the solar spectrum:
commercial glass used in building and has a total energy transfer of 87% that is to say, an SHGC of 87
Ultraviolet
UV
300 – 380 nm
1%
Visible
VL
380 – 780 nm
53%
Example:
SHGC of a specific glass = 30
Infrared
IR
780 – 2150 nm
46%
SHGC of 3 mm glass
= 87
The standard parameters for the calculation of the energy values
Therefore, the SC of the specific glass is 30/87 = 0.35
takes into consideration all three wavelenght bands from 300 to
The lower the SC, the better the glass performance.
2150 nanometers.
▲ 32
DEFINITIONS
THERMAL INSULATION The thermal insulation of a glass is denoted here by the U-values
set out in the EN 673 Standard and calculates the U-value using
and indicates the ambient conductive heat transfer through the
external heat-transfer co-efficient of 23 W/m2 K, and a solar
glass, given specific indoor/outdoor environment conditions.
radiation intensity of 500 W/m2 .
U-VALUES
The ASRAE Summer and Winter values are based on the measured
The U-value of glass is the inverse of the resistance R-value
values, and the RHG computed accordingly.(See p.34)
(U=1/R). ASHRAE (American Society for Heating, Refrigeration and Air-Conditioning Engineers) recognizes two different U-values:
All U-values are measured at the center of the glass. The use of
Hot Summer Daytime (for air-conditioned buildings) and Cold
thermal break aluminum profiles, PVC or timber frames will result
Winter Night Time (for heated buildings). The lower the U-value,
in better overall thermal performance of the glazing.
the better the performance of the glass. U-values are expressed in Btu/hr/ft2/ ̊̊ F (Imperial Units) and W/m2 K (Metric Units). The
Below are the environmental conditions set by ASHRAE for
conversion factor is 5.678.
computation of Summer and Winter U-values.
The European U-value (formerly K-value) is based on parameters
ASHRAE Standards Environmental Conditions Units
Winter Night Time
Outdoor Temperature
ºF
89
0
ºC
32
-18
Indoor Temperature
ºF
75
70
ºC
24
21
Wind Velocity
Mph
7.5
15
Kph
12
24
Solar Intensity
Btu/Hr/ft2
248
No Sun
W/m2
788
No Sun
▲
33
Summer Daytime
RELATIVE HEAT GAIN -RHG Relative Heat Gain is the amount of the total instantaneous heat gain through a glazing material taking into the account the effects of Solar Heat Gain Coefficient and conductive heat gain (U-Summer) The conditions formulated by ASHRAE consider a solar intensity of 230 Btu/Hr/sqft and an outdoor/indoor temperature difference of 14 ̊ F.
RHG = (SHGC x 230) + (U Summer x 14) Btu/Hr/Sqft. To obtain metric RHG in W/m2, multiply by 3.154
PERFORMANCE SPECIFICATIONS All performance specifications for CTI high performance units are calculated using the Lawrence Berkely National Laboratory’s program “WINDOW 5.2”, developed in conjunction with the U.S. Department of Energy (DoE), and the associated International Glass Data Base (IGDB) containing independently certified performance data for individual glass components. WINDOW 5.2 is a publicly available computer program for calculating total window thermal performance indices (i.e. U-Values, solar heat gain coefficients, shading coefficients, and visible light transmittances). WINDOW 5.2 provides a versatile heat transfer analysis method consistent with the updated rating procedure developed by the National Fenestration Rating Council (NFRC) that is consistent with the ISO 15099 standard.
■ 34
GLASS INTERIOR
GLASS MACHINERY
35
GLASS WORKFLOW
36
GLASS PROJECTS On Going Projects
THE WAVE, Oman
YASSAT TOWERS ELITE TOWER 7 STAR AL HAMRA HOTEL
Completed Projects
EMIRATES BANK TOWER
TRIDENT TOWER
CHURCHILL TOWER
37
■
DUBAI INTERNATIONAL FINANCIAL CENTRE
www.cladtech-int.com
UAE : Tel.: +971 7 244 61 14 Fax: +971 7 244 61 12 P.O. Box 6674 Ras Al Khaimah, UAE
KSA : Tel.: +966 (1) 219 05 66 Fax: +966 (1) 293 57 52 P.O. Box 18927 Riyadh, KSA