IGU Selection for Hot Climates
The key factors for buildings in hot climates are reducing heat gain from the sun to keep the building cool and keeping the cool air conditioned air inside the building.
- The performance of an IGU in reducing solar heat gain can be enhanced by using a solar control glass as the outer pane. The ability of tinted or reflective glass to control solar heat gain, combined with the added thermal performance of an IGU, maximises the reduction in solar heat gain.
- The performance can be further enhanced with the inclusion of Low E (low emissivity) glass, as the coating reflects heat energy and improves the solar heat gain and thermal performance of the unit. The Low E coating is used on surface 2 or 3 inside the unit depending on the glass combination and performance required.
- For hot climates it is advantageous to have the Low E coating on surface 2 (on a solar control glass), as the Low E coating acts as a barrier, reducing the transmission of heat from the outer layer of glass to the inside. Sometimes the Low E coating is used on surface 3 in combination with a standard solar control outer glass but this is less effective in controlling heat gain.
- Thermal performance is also important in hot climates to stop the cold air from air conditioning systems escaping. This is best enhanced by larger airspaces up to 16mm, using Argon Gas and/or Low E glass to improve insulation.
- Daylight and glare will be affected by the use of solar control and Low E glasses in an IGU as they both reduce the light transmission into the building.
7.3 Glasstech Double Glazing
GlassTech Double Glazing are Insulating Glass Units manufactured by Metro
GlassTech. They consist of two or more panes of glass separated around the edges by an aluminium
spacer and sealed at the perimeter in factory controlled conditions. The spacer contains
sieve desiccant (drying agent) which absorbs moisture vapour in the cavity.
GlassTech Double Glazing units are dual seal units comprising a primary seal of Polyisobutylene (PIB) to the spacer face and a secondary perimeter seal of Polysulphide. This results in a high quality IGU with a 10 year warranty suitable for commercial and domestic applications.
Insulating Glass Units filled with air.
Insulating Glass Units filled with Argon Gas.
GlassTech® Low E+
Insulating Glass Units comprising of Low E Glass.
Insulating Glass Units with the high tech and innovative Thermix warm edge spacer system, made from stainless steel and high performance engineering plastics.
Insulating Glass Units with a special silicone secondary
seal for exposed edge conditions, structural silicone glazing, and point fixed structural glass wall applications.
Insulating Glass Units with the Super Spacer Silicone Foam (SF) warm edge
spacer system. The black UV resistant silicone foam spacer incorporates molecular sieve desiccant
which combines the functions of a spacer, desiccant and corner keys. These units use hot
melt butyl as a secondary seal.