The numerical model proposed by Baritto (2010) for the prediction of temperature distribution in a flat plate solar air heater is presented in dimensionless form and solved for a wide range of turbulent flow operating conditions. A parametric study is performed and the outlet temperature is proposed as a function of the aspect ratios and the mass flow number. The proposed equation shows good agreement with experimental data. (C) 2011 Elsevier Ltd. All rights reserved.