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A STUDY OF WATER VAPOUR TRANSMISSION THROUGH INSULATION UNDER STEADY STATE AND TRANSIENT CONDITIONS.

Author(s) : GLICKSMAN L. R., KATSENELENBOGEN S.

Summary

A GUARDED HOT BOX HAS BEEN BUILT THAT ALLOWS ONE-DIMENSIONAL MOISTURE AND TEMPERATURE GRADIENTS TO BE INDEPENDENTLY SET ACROSS A TEST SECTION. COMPARISON OF A TRANSIENT TEST WITHOUT PHASE CHANGE TO AN ANALYTICAL SOLUTION FOR DIFFUSION ALLOWED THE DIFFUSION COEFFICIENT TO BE DETERMINED FOR WATER VAPOR THROUGH THE AIR-FILLED INSULATION. THE DIFFUSION COEFFICIENT WAS FOUND TO BE ALMOST TWO ORDERS OF MAGNITUDE LESS THAN THE VALUE FOR WATER VAPOR THROUGH AIR WITHOUT THE INSULATION PRESENT. CONDENSATION TESTS RUN WITH TIME-VARYING BOUNDARY CONDITIONS REVEALED THAT THE EXTENT OF THE CONDENSATION ZONE DURING CONDENSATION AND DRY-OUT IS NOT WELL REPRESENTED BY STEADY STATE RESULTS. THE WIDTH OF THE CONDENSATION ZONE INCREASED DURING DRY-OUT CONDITIONS, PROBABLY DUE TO CAPILLARY EFFECTS.

Details

  • Original title: A STUDY OF WATER VAPOUR TRANSMISSION THROUGH INSULATION UNDER STEADY STATE AND TRANSIENT CONDITIONS.
  • Record ID : 1985-0069
  • Languages: English
  • Publication date: 1983
  • Source: Source: ASHRAE Trans.
    vol. 89; n. 2A; 483-499; 15 fig.; 11 ref.; discuss.
  • Document available for consultation in the library of the IIR headquarters only.

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