Why is laminated glass a prerequisite?

We believe laminated glass is a prerequisite for rooflights when being installed above people's heads to secure you and your family.

The laminated glass is constructed by two glass sheets with a very thin layer of polyvinyl butyrate (PVB) between them. This enables the internal layers of laminated glass to absorb the energy of impact and resist penetration.

All our glazing units come with a laminated inner pane.

What is the difference between toughened and laminated glass?

Our rooflights are produced with toughened glass on the outside and laminated glass on the inside. Toughened glass is stronger than laminated glass of the same size and thickness. Toughened glass breaks into hundreds of tiny pieces, while laminated glass holds in place if shattered.

For this reason, we produce all our rooflights with a laminated inner pane to ensure optimum safety for you and your family.

What is Warm Edge Spacer technology?

All glazing units have a warm edge spacer to ensure a thermal break. Warm edge technology minimises the risk of condensation at the pane edges and provides the glazing units with the most durable insulation capabilities.

What is Uw-value and how does it differ from Ug-value?

The Uw-value indicates the insulating value of the rooflight construction. It is calculated as the heat loss through the entire rooflight construction.

The Ug-value, on the other hand, is the heat loss of the insulated glazing unit, measured at the centre point of the insulated glazing unit.

These two metrics are completely different. Ug-values are usually lower (better insulation), whereas Uw-values are somewhat higher because they measure the entire construction.

At Vario by VELUX, we indicate Uw-values as they give the most accurate representation of the installed product’s insulating properties. Ug-values only cover the glazing.

Vario rooflights come with Uw-values between 1.1 to 2.5 [W/(m²K)] and Ug-values between 0.5 – 1.3 [W/(m²K)].

To see all the specific insulating values of our rooflight constructions and glazing units, please see our technical table.

What is Sun Protection glazing?

Having too much heat or light enter through your rooflight can present as much of a problem as trying to keep heat in. Our Sun Protection glazing offers efficient reduction of solar heat gain.

The human eye easily compensates for the reduced light transmittance, which is approx. 20% less than our LowE glazing. There will be no green/blue tint, only a darker luminance.

Sun Protection glazing reduces heat gain by at least 30% – ideal for rooflights oriented towards the South or West.

To see all the values of our Sun Protection glazing, please see our technical table.