Glass Types
Float Glass (standard glass)
Float glass, also known as standard clear glass, serves as the base for most glass types. Typically, glazing uses clear float glass without additional coatings or insulation properties. Common thicknesses are 4mm, though 6mm and 10mm options are also available. Standard glass, when used without a low-emissivity (low-e) coating, has poor thermal insulation, which can lead to condensation build up inside a property.
Soft Coat (Low-Energy Glass)
Soft coat glass is float glass treated with a low-emissivity (low-e) coating applied to one side, which faces inward within the unit. This coating reflects heat back into the room, significantly improving thermal efficiency. To maximize this benefit, all of our units include Argon gas, which enhances insulation. Click here for more details. What's Inside Double Glazed Units
Soft Coat Application
Soft coat glass is our standard choice for low-energy units unless specified otherwise. The low-e coating is applied using a 'magnetron' coating line, where the coating is deposited onto cold float glass. This coating is delicate and easily damaged during production, hence the term "soft coat." During installation, approximately 15mm of the coating is removed along the perimeter (a process known as edge deletion) to ensure the sealant bonds directly to the glass, maintaining unit integrity. Soft coat glass provides superior thermal insulation compared to hard coat glass.
External Condensation
As nights grow colder, it is common to see condensation on the exterior surface of high-performance glazing. This phenomenon, known as external condensation, is a natural result of improved insulation, often mistaken for condensation within the sealed cavity (a sign of a failed unit). External condensation is short-lived and dissipates as the day warms. It visually indicates the effectiveness of the glazing, as the insulation prevents indoor heat from warming the outer glass surface, creating a cold exterior surface where moisture condenses. In contrast, older windows (standard glass) lose more heat, which warms the external pane and prevents condensation from settling. Condensation On Windows - How and Why It Happens
Understanding how high-performance windows reduce heat loss and lower energy costs is essential for homeowners, property managers, and anyone interested in the benefits of modern glazing.
If you currently have older low-energy glass, you may not experience external condensation to the same extent as with modern low-energy glass. This is because older glass is less effective at retaining heat compared to its modern counterpart. Advances in glass technology have improved insulation and reduced heat transfer, helping to keep indoor glass surfaces warmer. Upgrading to newer low-energy glass will enhance energy efficiency, comfort, and internal condensation control.