0415 667 779

free measuring

IGUnit Glass


Double glazing involves creating an Insulated Glass Unit (IGU) by spacing two or more lites of glass apart and hermetically sealing them to form a single unit with an air gap. This air gap enhances the thermal performance of the glass, making double glazed windows and double glazed doors highly efficient in architectural applications. Commonly, an IGU consists of two glass panels, but triple glazing is used in very cold climates. These units, manufactured in Sydney, can be framed in a sash or frame and are essential for energy efficient windows.

The insulative properties come from the air space between the glass layers, which can be filled with air or inert gases like argon or krypton for better performance. Desiccants are used to prevent condensation and improve insulation. In some cases, a partial vacuum is created by removing most of the air, which drastically reduces heat transfer through convection and conduction, known as evacuated glazing. The air gap usually ranges from 8mm to 22mm, with 16mm being the optimal thickness.

Spacers keep the glass panes apart and house the desiccant to absorb moisture. Silicone sealant provides structural strength, while butyl sealant is the primary defense for the hermetic seal. Insulated window and door products, such as uPVC double glazed windows, offer numerous benefits, including lower energy costs, improved comfort, reduced condensation, and diminished fading of interior furnishings.

During summer, double glazed windows and doors with a low solar heat gain coefficient reduce heat entering the home, enhancing comfort and lowering cooling energy needs. In cooler seasons, these products create warmer interior glass surfaces, reducing frost and condensation. They also protect against UV rays, which can cause fading and degradation of materials like carpets, curtains, and artwork.

A film or coating applied to the glass surface can further improve heat and sound insulation. Made of polyester or metal, this film offers a reflective appearance and a one-way mirror effect, enhancing insulation and safety in case of breakage. Secondary glazing, a cheaper alternative, involves adding a layer of glazing inside the existing window for additional insulation.

Key Performance Requirements:

  1. Thermal Insulation: IGUs primarily reduce thermal heat transfer from the outside. The effectiveness depends on the dryness of the air inside the IGU and the quality of the hermetic seal. Dry air is a poor heat conductor, and the air gap significantly reduces heat conduction through the glass.

  2. Structural Strength: IGUs are heavy and must maintain strength, especially in structural glazing applications. The type and quality of spacers, sealants, and spacer joints are crucial for maintaining this strength.

  3. Fogging Protection: Properly manufactured IGUs provide better protection against fogging than single panes of glass. However, poor quality control can lead to fogging issues.

Key Quality Areas:

  1. Desiccant Quality: Using the correct type and quantity of desiccant is crucial for absorbing moisture and maintaining air dryness within the IGU. Contact with ambient air during filling must be avoided.

  2. Spacer Joints: Ideally, spacers should have no joints. Automatically bent spacers with a single side joint are preferred over multiple corner joints for better structural strength.

  3. Controlled Environment: IGUs should be manufactured in a controlled environment to prevent moisture absorption and dust entry.

  4. Sealant Quantity: The secondary sealant provides rigidity, and its quantity must be appropriate for the IGU size.

  5. Equipment: Proper manufacturing equipment is essential for producing high-quality IGUs that perform well over their lifecycle.

Spacer Thickness: Our IGUs are available in various thicknesses (6, 8, 10, 12, 15, 18, 24mm) to meet local requirements and exceed customer expectations. All our energy efficient windows and doors are meticulously manufactured in Sydney.