Energy efficiency

Double Gazing and Thermal Break 


Double glazing  are double  glass window panes separated by an air or other gas filled space to reduce heat transfer across a part of the building envelope.

The glass panes are separated by a "spacer". A spacer is the piece that separates the two panes of glass in an insulating glass system, and seals the gas space between them.

A spacer made of aluminum that also contains a highly structural thermal barrier reduces condensation on the glass surface and improves insulation, as measured by the overall U-factor

  • A spacer that reduces heat flow in glazing configurations may also have characteristics for sound dampening in urban areas subjected to irritating noise levels, such as near subways, trucks and airports.
  • Typically, spacers are filled with or contain desiccant  to remove moisture trapped in the gas space during manufacturing, thereby  lowering the dew point of the gas in that space, and preventing  condensation from forming on surface #2 when the outside glass pane temperature falls.
  • U-factor is the term used for the rate of heat loss in a window assembly.  A lower U-factor is an indication that the window has a greater resistance to heat flow and thus has better insulating properties.

A thermal break or thermal barrier is an element of low thermal conductivity placed in an assembly to reduce or prevent the flow of thermal energy between conductive materials. 

  • Separating the frame into two separate interior and exterior pieces joined with a less conductive material reduces temperature transfer. Thermal breaks (made of substantially rigid, low thermal conductive polyamide or polyurethane which is mechanically locked in aluminum window framing can be more than a thousand times less conductive than aluminum and a hundred times less than steel.
  • In addition thermal breaks can have the added benefit of reducing sound transmittance by dampening vibration

Did You Know?

The new National Building Regulations now enforces the introduction of the new Energy Efficiency Standards, namely SANS 10400-XA. This stipulates the minimum insulation requirements for thermal insulation products and their measured application in new commercial and industrial building sites.