In this study, a planetary MOCVD reactor was thermally analyzed and a numerical model was proposed to predict an actual thermal distribution, comparing the results between the numerical simulation and experiment. Numerical simulations were performed for various modifications, namely, the ceiling design and heat shield layout, to improve the heating efficiency. The reactors comprising the ceiling design and modified heat shield layout conserved 15% and 5% of the heating energy, respectively. This study provides a method for predicting the temperature distribution inside MOCVD chambers and evaluating the heating efficiency yielded by design modifications. These results could be used to expand and consolidate the design engineering knowledge database. (C) 2014 Elsevier B.V. All rights reserved.