The choice of glazing unit has a large effect on the overall performance of the product. All double glazed windows come with a high performance glazing system optimised for thermal efficiency, resulting in increased light coming into your property.
We have a wide range of glazing options available including obscure patterns, acoustic reduction, solar reduction and enhanced thermal performance (a triple glazed system is available). There is also a wide range of lead and coloured glass options.
Thermal Loss (U-Value)
The U-Value of the glass is influenced by:
The coating on the glass – As standard we use Saint Gobain Total glass which has a softcoat coating. It has a very good centre pane U-value coupled with excellent solar gain performance and has a neutral look. We also have a wide range of options including self-cleaning glass and solar control glass to achieve the exact performance characteristics required.
The type and width of spacer bar between the 2 pieces of glass – The spacer bar forms the perimeter of the glass providing the spacing between two panes and the cavity seal to ensure gas is retained. As standard glazing units have an aluminium spacer, which while cost effective, provides poor insulation and as a result a poor U-value. Alternatively you can use a warm edge spacer bar which is manufactured from more thermally efficient material. It reduces the thermal bridging effect at the edge if the glass and produces a significantly better overall U-value.
The medium in the cavity (gas or air) – We have a large choice of sash widths so the cavity width can be changed. Usually a width of 16mm with a filling of argon gas will provide good performance at a competitive price. Krypton can provide a better performance but this is only significant when the cavity width is very small when specifying a slim line or a triple glazed unit.
Thermal Gain (Solar Gain)
Solar gain is due to the amount of thermal energy transmitted through the unit to heat the inside of the building. In the UK, this has a very positive effect and as a result a high performance softcoat glass is usually the best choice.
However, there are a number of situations where the solar gain has a negative effect on temperature control especially if an increase in air conditioning is then required. In these situations solar control glass is more beneficial, allowing the sun’s impact to be restricted giving a reduced and more consistent heat flow.
Acoustic performance is affected by the thickness of the glass, the gas cavity width and the material used in the centre of laminated glass. We have carried out a wide range of tests using systems in different sash widths and can provide technical help and data to deal with individual requirements.
Toughening coated glass has been a problem in the past but the latest products allow for the coated pane to be toughened. This has benefits over laminated glass as it is cheaper and is more consistent with other units that do not have safety requirements.
As well as our extensive range of clear glass options, we have a wide range of obscure patterned glass options. The glass is available in five levels of privacy which are rated from 1 (least obscuration) to 5 (greatest obscuration).