Condensation will occur on
any surface with a temperature less than the dewpoint of the atmosphere
near the surface. Therefore, when the surface temperature of any part of
the patent glazing and the relative humidity of the atmosphere reach a critical
combination, condensation will occur.
Ground frost, cold rain and
low temperature with high wind will exacerbate the formation of condensation.
Adequate ventilation will serve to reduce condensation. Inside buildings,
the humidity will be increased by the release of moisture from cooking of
food, the presence of people or a large body of water, such as a swimming
This moisture can reach high
levels where ventilation is inadequate. The possibility of condensation
forming on glass may be minimised by using double glazed units with a low
U Value, combined with a thermally broken glazing bar such as the Skyline, Skyline Box and Rafterline
For a more in-depth explanation of Condensation,
the GGF (Glass & Glazing Federation) have published an interesting
document, which can be viewed
from this site.
Here' to view the full GGF booklet as a Acrobat Reader file