High Altitude Capable - Double glazed glass - Insulated Glass Units - High altitude windows

[diegop]

Hi all!
I´m trying to spec several double glazed glass panels for my Expedition truck
These panels will be manufactured at sea level and should be able to travel and stay at 4500m above sea level for a month, without breaking. It is ok for the glass to bend.
I´m in Argentina, I can get glasses of most any thickness, tempered, laminated, standard, LowE, etc.
What I cannot find locally are valves or suppliers that understand how to use them.

Windows size will be 1000m x 500m aprox.

I understand that KCT and Outbound support these heights, but don´t know how they do it.

Any help is very much appreciated!

 

[Pinnacle Campers]

Hi all!
I´m trying to spec several double glazed glass panels for my Expedition truck
These panels will be manufactured at sea level and should be able to travel and stay at 4500m above sea level for a month, without breaking. It is ok for the glass to bend.
I´m in Argentina, I can get glasses of most any thickness, tempered, laminated, standard, LowE, etc.
What I cannot find locally are valves or suppliers that understand how to use them.

Windows size will be 1000m x 500m aprox.

I understand that KCT and Outbound support these heights, but don´t know how they do it.

Any help is very much appreciated!

Most residential stuff uses capillary tubes during transportation, here is an article I found, https://www.303windows.com/windows-denver-colorado/colorado-replacement-windows/
Good luck and share what you learn.

 

[diegop]

Thanks for the answer Brian. Those tubes are used just for transportation but must be sealed once installed, otherwise humidity will get into the glass panel. Some valves on the other hand, seem to handle this better, and could be a viable solution, but i cant find them here. I’m trying to stress the “glass only” option.


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[tanuki.himself]

Do you need to keep them sealed? i would be more inclined to allow the pressure to equalise and build in a way to hold some desiccated silica gel in the breather hole to remove any moisture that could cause condensation.

 

[diegop]

Those valves y mentioned go through the secondary, exterior seal and end up in the dissicant part (like silicagel) of the panel, doing pretty much what you suggest.


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[tanuki.himself]

Sorry, I'm still not sure what the benefit of valves is over just holes that allow the air inside to expand and contract. Do you mean something like a schraeder tyre valve? Personally I would just have something to hold the desiccant over the holes on the outside of the spacer so it can easily be removed to dry it or replace it if necessary, and be able to blow the old air out with something like an aerosol can of dry clean air. Unless you are going for something like argon filled where the only air is just to allow for the pressure change, in which case some sort of internal rubber bladder that can absorb the pressure differentials built into the spacer may work.

this is all still theory for me - not sure if I am going to buy or build my own windows from scratch-resistant acrylic to save weight, but I have been giving it some thought for a while

 

[luthj]

On aircraft we just put a small (1mm) hole at the bottom of the inner pane. You may get a small amount of transient fogging, but nothing serious. (Assuming the outer panel doesn't leak water).

 

[NatersXJ6]

I suspect you may be over thinking this.

You are probably better off to just get solid laminated windows. In that case, the glass is bonded to a poly-vinyl backer and baked in an autoclave. This is the process for making “bulletproof” glass, as well as transportation glass like windshields. An added benefit is that the glass won’t shatter into the passenger space in case of breakage. You give up a bit of insulation value to thermal conductivity, but maybe not as much as you imagine. Do some research on the insulating value of laminated versus IG glass and see if it is acceptable. Generally, compared to the rest of a vehicle build, I suspect it will be acceptable.

If you insist on using IG units (with an inert gas or air gap) then use really thick glass to resist the pressure changes, and consider vacuum insulated versus gas insulated, however... weight will become an issue, and all seals will be at risk of leaking eventually.

Any usage of valves will cause issues of corrosion, mold, etc as air exchanges between the panes.

I know some glazers, and will ask around, but I suspect they also won’t know or deal with valves, as architectural glass tends to stay where it is installed.

 

[luthj]

The aircraft windows are double pane polycarbonate (acrylic sometimes). A small amount of fogging or frost will happen with rapid temp or altitude changes.

 

[NatersXJ6]

So I asked around my glass industry and glazer contacts. They have seen the valves you are talking about but never bothered with using them because once architectural glass reaches altitude it is never messed with again. They seemed to think that you should be more worried about seal integrity than glass strength (your early post makes it sound like you were) and that a permanent opening similar to the hole in aircraft windows or solid laminated were the best choices versus trying to manually or automatically equalize with valves.

 

[goodspeed]

Hi there. Have you found an answer to your question? As far as I know, at higher elevations. atmospheric pressure can cause glass panes to bow outward. You have to be very careful and prepared for everything. I had a house on a pretty high altitude, and I have used some special glasses for the windows. However, everything was fine, but the biggest problem was to clean them somehow. I couldn't do it by myself, and that's why I was always ordering cleaning services from https://leedswindowcleaningservices.com/. These guys really know their job. They made my windows looking perfect.