If you bring a properly manufactured insulation glass to a higher elevation the enclosed gas expands due to the lower atmospheric pressure. An overpressure is evolved In the cavity that bends the glasses and puts pressure on the edge bond. This might lead to breakage, but it surely reduces the lifetime of the insulation glass - depending on the construction and the altitude difference. Another negative side effect is the distorted reflection.
Pressure balance of insulated glass is becoming ever more frequently necessary due to the constantly increasing proportion of triple glazing, larger formats, asymmetric structures and long transport paths. Depending on the structure, pressure balance is recommended starting with a difference in altitude of 400 - 500 meters between the production site and the installation site.
This is no problem! With the HELANTEC ISO-Altimeter PROFESSIONAL you can execute this task in no time at all. Using the ISO-Altimeter PROFESSIONAL the IG unit is prepared in production in such a manner that it is flat at the higher (or lower) altitude of the installation site. Additional after-treatment is not required!
The HELANTEC valve is a small but important detail. Only with this valve can it be ensured that the executed pressure balance remains intact and that your assured characteristic of the IG unit does not change.
In former times those were the only solution - despite its cumbersome installation. A small metal tube is put into the spacer bar while the far end connects to the air. Depending on the over-pressure or under-pressure in the DGU a certain amout of gas or (moist) air can continuously leave or enter the space between the glasses. Sooner or later, there will be no more gas but pure air. So the insulation value is less than at the beginning. Plus, the desiccant has to aborb a lot more moisture. A shorter lifetime is the result.
You can close the capillary tube at the installation place, but only if you get access to it. This would be possible with structural glazing but proofs difficult with completed windows.
Pressure release valve, breathing socket:
At a certain value of pressure the valve opens and releases or gas or introduces air. So again, the insulation value and the lifetime of the DGU are reduced.