Used to create the airspace between the two panes of glass and hold the molecular sieve (desiccant), spacer bar also helps to maintain a unit's structural integrity. It is available in a range of widths and lengths.
Small perforated lines run down the centre of spacer bar around its inner surface. Breather holes allow the passage of gas into the spacer bar where desiccant is held.
Alternatively, foam spacer can be used which is pre-desiccated and requires no corner keys or connectors.
Several types of spacer bar are available including: Aluminium , warm edge and steel profiles in many colours. Warm edge bar offers a more thermally efficient solution. Those supplied by Thermoseal Group include: Thermobar, Thermobar LITE, Thermoflex and Thermix-TX.N.
Spacer bar can be bent or joined at the corners. Connectors and corner keys come in a range of sizes and colours which are compatible with specific profiles of spacer bar. Gas fittings are also available.
Inside the spacer bar, thousands of beads of desiccant are held. The sole function of the desiccant or molecular sieve is to absorb any moisture in the airspace and keep the moisture from condensing on the inside surfaces of the glass. A pure 3A desiccant is the best solution. Thermoflex warm edge foam spacer contains a desiccant compound.
A dual sealing system makes up for over 90% of the European insulated glass market. The primary seal serves as an assembly support during the construction of the sealed unit. Once completed, low moisture vapour transmission rate and low gas permeability help stop the movement of water vapour and inert gases in and out of the sealed unit. Primary sealant is available in several block sizes and is compatible with butyl, PU, PS and Silicone systems.
An edge sealant bonds to the spacer bar and the glass to seal the edge of the unit to prevent moisture ingress. It also provides protection from gases passing into and out of its internal unit construction. Options include: Hotmelt, Polyurethane, Polysulphide and silicone. This is critical to the integrity of the sealed unit.
Sealed units are often filled with an inert gas such as Argon. Gas-filled units are considered more thermally efficient and are often referred to as 'high performance' (providing the unit is constructed with an emphasis on preserving the gas within it).
The requirement to pass EN1279 part 3 standard and the pressure to gain a C+ Window Energy Rating (WER) is creating an increasing demand for units that are gas-filled.
Adding Georgian grille and bar to the internal and/or external construction of a sealed window unit is a simple way to replicate classic old Georgian style windows. Georgian bar is stapled to or secured by drilled fittings to the spacer frame of the sealed unit and it is then sealed between two pieces of glass to create a Georgian design.
There is a variety of other options available to decorate your glass and give your windows a unique design including: lead strip (available in a range of colours), coloured films, coloured resins and a multitude of decorative glass bevels which are bonded using special UV adhesives.
Specialist blinds to be integrated within insulated glass sealed units are now available to sealed unit manufacturers as a complete kit including: specialist spacer bar (cut to size), corner keys (gas keys available) and the blind itself.
These blinds can be integrated within a glass sealed unit and operated without compromising the hermetic seal of the unit. They are most suited to gas-filled units. Click here for further information.