When double glazing was first introduced into South Africa, many manufacturers followed the European method of manufacturing double-glazed units using Argon gas between the two panes of glass. This was largely because double glazing in Europe is designed primarily to improve insulation against very cold external temperatures and to retain heat inside buildings.
How does this differ in South Africa?
South Africa has a very different climate to much of Europe. While we certainly experience cold conditions, our buildings are generally more concerned with reducing solar heat gain and keeping excessive heat out, particularly during our warmer months.
Argon gas is an excellent insulating gas and can improve the thermal performance of a double-glazed unit. However, it is important to understand that Argon is not a permanent component of the glass unit. Over the long term, small amounts of gas can migrate through the sealed perimeter of the unit, depending on the quality and construction of the sealed unit.
What about double glazing made with air?
A properly manufactured double-glazed unit does not simply contain ordinary atmospheric air trapped between the panes.
During manufacture, the two panes are assembled in a highly controlled environment. The air space is carefully controlled and the unit is sealed around its perimeter. A desiccant is incorporated into the spacer system to absorb residual moisture and help keep the internal cavity dry.
The result is a sealed, dry insulating cavity between the two panes of glass.
Argon vs Dehydrated Air
Both systems provide an insulating barrier between the two panes of glass. Argon has a lower thermal conductivity than air and can therefore provide improved thermal insulation when the unit is correctly manufactured and remains properly sealed.
However, for the South African climate, the choice between Argon-filled and dehydrated-air double glazing should be considered together with the glass specification, solar-control properties, orientation of the building, frame system and overall window design.
Double glazing is not simply about putting two panes of glass together. The performance of the complete system depends on all of these factors working together.
The quality of the sealed unit matters
Whether Argon or dehydrated air is used, the quality of manufacture and the integrity of the perimeter seal are extremely important. A correctly manufactured double-glazed unit should remain dry and sealed throughout its service life.
At Peninsula Glass, we can only manufacture units with dehydrated air as they have long lasting qualities.