SEDL / STP / STP217-EB / STP43657S

Thermal Conductivity of Insulation Containing Moisture

Joy, F. A.
Professor of Engineering Research, The Pennsylvania State University, University Park, Pa

Pages: 16    Published: Jan 1957

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Abstract

A transient heat flow method based on the theory of an infinite line heat source was found suitable for the measurement of the thermal conductivity of insulation containing moisture. The measurement is fast and the temperature rise small. The results indicate, however, that vapor movement is not eliminated and that the measurement includes a latent heat effect as well as sensible heat conduction.

The thermal conductivity of three representative insulating materials was tested in a wide range of moisture content at two temperatures—above and below freezing. These results suggest that the properties of an insulation, especially its vapor permeability, characterize its behavior when wet.

The information presented is of a fundamental nature not suitable for immediate use in field installation problems.