The phase change problem has been extensively studied because of its wide range of applications in engineering problem. The major characteristic of the phase change problem is that there exists a solidliquid interface which is continuously moving due to the difference of the heat fluxes at the interfaces. The main purpose of this work is to obtain the transient solidified layer thickness along the outside wall of a cooled-tube and the transient temperature along the inside wall of a cooled-tube at various locations to compare with the predictions of the minimization method proposed earlier. Another objective of this experimental study is to evaluate the magnitude of the natural heat transfer coefficients when solidification of an initially stagnant fluid is taking place on the outside wall of a cooled channel. The results of the comparison between the present experimental results and the predictions of the minimization method developed by earlier workers show a good agreement.