Condensation problem with cheese case

[FEISTY]

Greetings to all !! I have a wall hung pie case that was " custom built " to fit and designed for displaying cheese. 2 sliding doors about 15" high by 24" long. Doors are thermopane glass with almost all plastic frame. I have heavy condensation on OUTSIDE SURFACE OF BOTH DOORS ONLY AT BOTTOM. Sweat is on glass and about 1 1/2" high. Is there a way to test if vapor between glass panes is lost ? Glass doesn't feel that cold on outside. Wiper seals new and tight. Inside temp 37-40 degrees F. Room is a/c controlled and about 72 degrees F. Thanks for any advice. Have a good day !!

[Yuri B.]

Hi Feisty.
Evidently, what there in the thermopane should have been - rarified air, or some other gas - is now lost.

[lowcool]

heat transfer i'd say,if theirs no moisture on the inside of the glass your vapour seal should still be fine.bottom of the cab you would expect to be the coldest also the door track would be the largest part for air leakage,is assume its a static coil or is it forced draft ?

[Yuri B.]

Frost at winter appears on a window without seal inside the room, not between panes.

[lowcool]

i only assumed that thermopane glass is double glazed ie two pieces of glass sealed with a barrier in between them,after all he is talking about the outside surface,the glass ?,given outside air is warmer than cabinet i would expect moisture to form on an uninsulated or non heated surface let alone air escape

[FEISTY]

Thanks for all the viewpoints. Glad my problem caused conversation. Here is more infomation. Unit is air flow cooled. Cold air enters at bottom rear of case. Opening has been restricted by aftermarket baffle to only allow approx. 30-40% of full flow of cold air. I cannot explain reasoning of work but have guess that oversized refrigeration system used in " custom sized " case. Unit was built to fit space. Builder of unit should have reversed idea and built space to fit properly sized refrig. system. Frame of doors is plastic/vinyl material and doors heavy enough to weigh down to seal against round track. Finally...no moisture forms on INSIDE OF ANY SURFACE. All moisture is at bottom OUTSIDE SURFACE of both doors with pattern indicating more sweat at meeting joint of closed doors. It is at botton center of both doors and spreads out but gets less farther away from center. Probably some sort of draft leak but tries " duct smoke " inside and , running evap fan , couldn't find leak [s]. Please don't go crazy over this. Already supplied customer with different unit as answer and am waiting for ok. It is just that I am not happy with a problem and no solution. Have a great day & thanks again.