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sainty
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Pressure differentials in Double Glazing Units
Hi
I hope I'm in the right place. I'm also hoping that this problem will appeal to someone! I'm a joiner and I make windows. I am in a discussion on a woodworking forum about the physics of a double glazed unit and it's starting to go above my basic understanding!
The crux of the discussion is that DG units fail when condensation appears on the inside of the unit. A DG unit is made up from 2 pieces of glass separated by a spacer, to create the gap which contains a desiccant. A sealant is then applied around the unit to make it "air tight". We believe that temperature fluctuations cause pressure in the units that make the sealant "fail" and leak (tiny holes?), this then exchanges the dry air in the unit to be replaced by new moist air. This exchange continues until the desiccant becomes saturated. At this point the failure occurs and condensation appears.
Firstly, does this sound feasible? Given a 20 degree C temperature differential, what sort of pressures are exerted on the unit and what volume of air is required to equalise the pressure in the unit. Lastly, what could be done to prevent the premature failure of DG units?
Thanks in advance for any help received.
Rgds
Stuart.
Hi
I hope I'm in the right place. I'm also hoping that this problem will appeal to someone! I'm a joiner and I make windows. I am in a discussion on a woodworking forum about the physics of a double glazed unit and it's starting to go above my basic understanding!
The crux of the discussion is that DG units fail when condensation appears on the inside of the unit. A DG unit is made up from 2 pieces of glass separated by a spacer, to create the gap which contains a desiccant. A sealant is then applied around the unit to make it "air tight". We believe that temperature fluctuations cause pressure in the units that make the sealant "fail" and leak (tiny holes?), this then exchanges the dry air in the unit to be replaced by new moist air. This exchange continues until the desiccant becomes saturated. At this point the failure occurs and condensation appears.
Firstly, does this sound feasible? Given a 20 degree C temperature differential, what sort of pressures are exerted on the unit and what volume of air is required to equalise the pressure in the unit. Lastly, what could be done to prevent the premature failure of DG units?
Thanks in advance for any help received.
Rgds
Stuart.
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