Sealed units also known as insulated glass units (IGUs)—are the backbone of modern energy-efficient glazing. Here's a breakdown of what they are and why they matter:
🧊 What Is a Sealed Unit?
A sealed unit is a multi-pane glass assembly designed to improve thermal insulation and reduce energy loss. It typically consists of:
Two or more panes of glass (double, triple, or even quadruple glazing)
Spacer bars between the panes, often filled with desiccant to absorb moisture
Gas-filled cavity (commonly argon) to enhance insulation
Primary and secondary sealants to create an airtight, moisture-resistant bond2
🛠️ How They're Made
The process involves:
Cutting and cleaning the glass panes
Applying spacer bars and desiccant
Sealing the unit with high-performance sealants
Optionally filling the cavity with insulating gas
Adding coatings like low-emissivity (low-e) or solar control for enhanced performance
🌡️ Benefits
Thermal efficiency: Keeps homes warmer in winter and cooler in summer
Noise reduction: Multiple panes help dampen sound
Condensation control: Desiccants and airtight seals prevent fogging
UV protection: Coatings can reduce harmful UV rays
🧱 Structural & Architectural Use
In commercial settings, sealed units can be part of frameless or toggle glazing systems, offering sleek aesthetics and structural integrity. These units can be custom built with toughened or laminated glass, painted borders, and self-cleaning finishes.
⚠️ When to Replace
Signs your sealed unit may need replacing:
Fogging or condensation between panes
Cracked glass or broken seals
Draughts or noticeable temperature shifts near windows
