• Low-E stands for “low emissivity”, which means that the glass has a low rate of emitting radiant heat.
• Low-E glass is coated with a microscopically thin, transparent layer of metal or metal oxide. This coating reflects heat back to its source, keeping heat inside during winter and outside during summer.
• Low-E glass can have different levels of solar control, which determines how much visible light and solar heat can pass through the glass. This is measured by two metrics: visible light transmission (VLT) and solar heat gain coefficient (SHGC).
• Low-E glass can also have different levels of U-value, which measures how well the glass insulates. The lower the U-value, the better the insulation.
• Low-E glass can help reduce energy costs by reducing the need for heating and cooling, and can help regulate the temperature and humidity inside a building.

Online Low-E Glass:

• Online Low-E glass is produced by applying a thin layer of metallic oxide during the glass manufacturing process.
• The coating is fused to the glass while it is still in a molten state, resulting in a durable and scratch-resistant surface.
• Online Low-E glass has a higher solar heat gain coefficient (SHGC) than Offline Low-E glass, meaning it allows more solar energy to pass through the glass.

Offline Low-E Glass:

• Offline Low-E glass is produced by applying a thin layer of metallic oxide to pre-cut glass sheets.
• The coating is then cured in a heat treatment process, resulting in a durable and scratch-resistant surface.
• Offline Low-E glass has a lower solar heat gain coefficient (SHGC) than Online Low-E glass, meaning it allows less solar energy to pass through the glass.