A new experimental procedure is proposed based on an instrumental variable method [1] for analyzing wall surface heat transfer processes and deducing wall surface heat transfer coefficients under actual conditions. Tests were carried out under a wide range of conditions, and the heat transfer coefficient was found to vary from 8 to 26 W/m(2) K while wind speed ranged from 0 to 7.5 m/s, and correlations were obtained in terms of wind speed. In addition, the experiments indicated that wind direction does not have a significant effect on the heat transfer coefficient of wall surfaces.