Differences in temperature, climatic stresses and especially differences in altitude typical for high mountains areas lead to build-up of excess or negative pressure within insulated glass. The resulting tension and excessive loads can lead to glass breakages and premature ageing. With AIR vent, the simple component implemented in edge of glass spacer, this tension is greatly reduced, as it equalizes and balances the pressure between the surrounding environment and the insulated glass and therefore offers a higher degree of safety.
In the case of seasonal climatic loads, AIR vent helps to ensure that the maximum permitted tensions in the glass are not exceeded and thus the visual distortions in windows and doors – are reduced.
Height (altitude) differences
AIR vent equalizes the pressure between the surrounding air and the cavity between the panes and thus minimizes, for example, the risk of breakage when transporting units over significant differences in height high above the see level. We recommend start using AIR vents >650 m over sea level.
A comparison of glass units with and without AIR vent
AIR vent is a metal sleeve with an integrated special membrane. Its special structure prevents water vapor from being able to accumulate inside the glass unit, which would otherwise lead to the formation of condensation or damage the Low-E coatings. The insulated glass unit retains its function and quality over the long term through permanent pressure relief.
What happens with the glass unit in the event of temperature and altitude differences?
In the cold and low heights – air contracts and the glass panes bend inwards and the AIR vent equalize the tension:
In the heat and high heights – air expands, and the glass panes bend outwards. The AIR vent leads the tension out:
Without AIR vent / With AIR vent
Basic recommendations for the glass units with AIR vent:
AIR vent is required in each warm spacer if it’s 3-layer glass;
External glass sheets should be 2mm thicker than internal’s;
AIR vents should be used at least >650 m over sea level.
Any of our uPVC windows and doors can be equipped with AIR vent. Besides of main project’s requirements for U-value or sound reduction, it is also important to consider all possible risks and evaluate the building’s location before placing the order.
Just recently we have updated main uPVC windows and doors catalog revealing our full range according to uPVC products categories including all available series: ARCTIC, E-PASSIVE, ARCADE, NORDLINE, ELEGANT and PRESTIGE.
We start October with improvements for our entrance and terrace doors. Starting from 02.11.2020 new design hinges Dr.Hahn KT-V 6R will be implemented on terrace and entrance doors: ARCTIC, E-PASSIVE and ARCADE. Take a glance at all visual and technical benefits.