Analysis of the Effect of Relative Humidity on the Convective Heat Transfer Coefficient Using Full-Scale Experiments in a Climatic Wind Tunnel

Abstract

The effect of relative humidity on the convective heat exchange between a solid surface and an ambient air stream is analyzed in this study. In the experimental part, a unique closed-circuit climatic wind tunnel is utilized, allowing full-scale experiments to be conducted with full control over the environmental parameters defining the experimental boundary conditions. The experimental configuration, which includes a specific design of a specimen to promote a controlled heat flow through the specimen body, might bring new insights into the field of energy-related calculations or prediction of building energy consumption. The novelty of this work lies in the implementation of relative humidity as an independent factor within thermal modelling, which might contribute to increasing the accuracy of building energy simulation models. The computational analysis of experimental results indicates relative humidity as an important parameter, which can affect the convective heat transfer coefficient by up to 37%. The major effects have been observed after exceeding a relative humidity of 50–55%.