Natural convective heat transfer coefficient - a review I. Isolated vertical and horizontal surfaces

Natural convective heat transfer coefficients have been the subject of study for more than a century. During this period, a large number of correlations have been developed to fit the heat transfer data. Of interest to building modellers are those which deal with the convective heat transfer coefficient on vertical and horizontal surfaces. This paper presents an extensive review of studies about the natural convective heat transfer coefficient on isolated vertical and horizontal surfaces with special interest in their application to building geometries. Comparisons between correlations for the heat transfer coefficient showed that large discrepancies could occur. The discrepancies are found to be up to a factor of 2 for isolated vertical surfaces, up to a factor of 4 for isolated horizontal surfaces facing upward, and up to a factor of 4 for isolated horizontal surfaces facing downward. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.