Methods of human thermal comfort analysis are based on the heat exchange conditions between the human body and its environment. In the present study a three-dimensional computational fluid dynamics (CFD) model simulated the steady state dry heat loss from a human body located in a chamber is proposed. The CFD model was validated by comparison with experiments performed by placing a thermal manikin in an environmental chamber. The proposed numerical model achieved good agreement with the experimental data, with a relative percentage difference within ±5% indicating excellent accuracy. Three dimensional fluid flow, temperature distribution, heat transfer between human body and ambient, radiation and convection heat transfer rates on human body surfaces, average convection and radiative heat transfer coefficients were calculated in this study. Results of calculations were in agreement with the available theoretical data in literature.