Insulated Glass Unit – IGU

Double glazing through the use of Insulated Glass Units (IGUs) significantly improves the thermal performance of windows, keeping warmth in throughout winter and heat out during summer.

Also known as DGUs (Double Glazed Units) IGUs are window units made of multiple glass panels, sealed with a spacer and gas between them.

INSULATED GLASS UNIT COMPONENTS

IGU Build Up

Glass – Glass in an IGU is used to provide natural light and maintain internal temperature conditions and protection from outside conditions.

Spacer Bar – Glass panels in an IGU are separated by a ‘spacer’. Spacers can be found in a number of materials, each of which has an effect on the performance of the IGU. They are often made of aluminium or an insulating plastic composite known as warm edge spacers.

Warm edge spacers get their name because they are more insulating and not as conductive as aluminium spacers. Current available materials are aluminium, steel, stainless steel, thermoplastic, and plastic.


Gas fill
– To improve the performance of an IGU, gas filling is an option provided by manufacturers. Inert gasses such as Argon and Krypton are used in place of just air in the internal cavity of the unit.

Sealants – Sealants are used in the construction of an IGU in two stages. A primary seal is used to fix the glass panels to the spacer bar, and a secondary seal is used to seal the outer edges of the complete unit. The sealants purpose is to prevent moisture penetration into the unit. Primary sealants are often used in conjunction with aluminium spacer bars and act as a barrier to stop thermal transfer from the two glass panels touching it. Warm edge spacers are often applied with a self-adhesive primary seal, and due to their material makeup are already far less conductive than their metal alternatives.

The secondary seal (outer seal) is always required when constructing an IGU. It provides structural strength to the IGU edge. Secondary sealants generally come in the following variants; hot melt butyl, two-part polysulphide, two-part polyurethane and silicone.

PERFORMANCE DATA DEFINITIONS

IGU Performance

Hot Air always moves towards cold air. By reducing the loss of heat from the warm side to the cold side of the window, IGU’s can reduce the heat loss in cold weather, or vice versa.

VLR: The percentage of visible light that is reflected from the glass surface(s).

VLT: Expressed as the percentage of visible light that is transmitted through a glass type

SHGC: Solar Heat Gain Coefficient. The proportion of directly transmitted and absorbed solar energy that enters into the building’s interior. The lower the number the better the glass is able to exclude solar radiation.

U-Value: The measure of air-to-air heat transfer (either loss or gain) due to thermal conductance and difference between indoor and outdoor temperatures. The lower the number, the better the insulating qualities of the glass.

SOUND PERFORMANCE OF IGUS

If you require sound proof glass, IGUs have many benefits compared to single glaze windows, one of which is its sound insulating ability. Changing the thickness of glass used in the IGU or combining a laminated glass panel can greatly improve the insulating properties of the IGU.

Compare the sound insulation characteristics of the following configurations:

IGU sound performance

Configuration 1:
• This would have the least amount of sound insulation.
• 6mm Clear Float window has a rating of 31 (Rw)

Configuration 2:
• This would have a better sound insulation, but not the best.
• 6mm + 12mm spacer + 6mm IGU has a rating of 34 (Rw)

Configuration 3:
• This build up uses glass panels of different thicknesses. Due to the change of thickness the frequency dampens significantly when passing through, giving improved acoustic performance.
• 10mm + 12mm spacer + 6mm IGU has a rating of 36 (Rw)

Configuration 4 – Optimal IGU Configuration:
• This build up provides even better performance in sound insulation and a thinner and lighter IGU. The build-up uses an acoustic laminate glass to provide better acoustic performance and an overall thinner and lighter IGU.
• 6mm + 12mm spacer + 6.5mm IGU has a rating of 38 (Rw)

Rw: Weighted Sound Reduction Index. It is a number used to rate the effectiveness of a soundproofing material. The higher the Rw number, the better a sound insulator will be.

Our Insulated Glass Unit Products

ToughECO™

Eliminate everyday expenses when using air conditioning or heaters to better climatize your home. ToughECO™ is our entry level insulated glass unit that will assist in keeping your home warmer in winter and cooler in summer. In addition, ToughECO™ provides basic acoustic performance helping reduce unwanted external noise.

Common Applications
  • Residential Windows & Doors
Features & Benefits
  • Provides better comfort in your home
  • Reduction in heating and cooling bills
  • Acoustic properties assisting with noise reduction
  • Reduces condensation eliminating risk of mould build up
  • Elegant spacer providing enhanced aesthetics
Capabilities
  • Minimum Size: 400 x 200
  • Maximum Size: 2000 x 3000
Selection & Specification
  • Glass Availabilities: Clear, Low Iron, Toned, Obscure, Patterned, Hard Coat Low-E
  • Glass Thickness: 4mm, 5mm, 6mm, 10mm
  • Spacer Type: Super Spacer®
  • Gas Selection: Air or Argon (recommended)
  • Spacer Selections: 6 – 20mm (2mm increments)
  • Secondary Seal: Hot Melt Butyl or Silicone
Considerations & Recommendations
  • Select different glass thicknesses in the build up to improve noise reduction.
  • Framing selection must be considered as overall performance may be affected.

ToughECO™ Plus

ToughECO™ Plus is our advanced insulated glass unit providing increased economical solutions for your home. We have selected a high performance, soft coat glass to use when building the IGU to provide high light transmittance and an advanced energy efficient unit.

Common Applications
  • Residential Windows & Doors demanding higher energy efficiency
Features & Benefits
  • Increase your home energy rating
  • Premium light transmission
  • Provides better comfort in your home
  • Reduction in heating and cooling bills
  • Reduces condensation eliminating risk of mould build up
  • Acoustic properties assisting with noise reduction
  • Elegant spacer providing exceptional aesthetics
Capabilities
  • Minimum Size: 400 x 200
  • Maximum Size: 2000 x 3000
Selection & Specification
  • Glass Availabilities: Clear soft coat combined with, Low Iron, Toned, Obscure, Patterned
  • Glass Thickness: 4mm, 5mm, 6mm, 10mm
  • Spacer Type: Super Spacer®
  • Gas Selection: Air or Argon (recommended)
  • Spacer Selections: 6 – 20mm (2mm increments)
  • Secondary Seal: Hot Melt Butyl or Silicone
Considerations & Recommendations
  • Select different glass thicknesses in the build up to improve noise reduction.
  • Framing selection must be considered as overall performance may be affected.
What people are saying!
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