© The Author(s) 2017. In this study, experimental and numerical results of heat transfer in a ventilated cavity with an internal heat source are presented. The cavity represents a ventilated room with a person inside in a 1:3 scale. It has a vertical wall receiving a constant and uniform heat flux, while the opposite wall is kept at a constant temperature. The rest of the walls is adiabatic. The cavity has multiple inlets and outlets of air, considering ventilation by ducts of an air-conditioning system. Experimental temperature profiles were obtained at six different depths and heights consisting of 14 thermocouples each. Six turbulence models were evaluated against experimental data. The minimum average percentage differences between numerical and experimental average Nusselt numbers of the hot wall and heat source were 12.9% and 4.1% with the renormalized k–ε turbulence model.