Experiments were also used to estimate the heat transfer coefficient values of ambient environment over the outer walls of the menu box. In general, the heat transfer coefficient values for free convection of air ranges from 5 W/(m2•K) to 25 W/(m2•K) (Singh & Heldman, 2001). Based on this range, the heat transfer coefficient value of air over the outer walls of the menu box was varied in the numerical simulation, such that minimum error is achieved between numerical prediction and experimental data.