The present investigation deals with the natural, mixed and forced convection in a vented rectangular cavity having a sinusoidal heated vertical wall with a conducting solid block placed at one of the nine positions. The objective is to analyze numerically using finite element method the effects of the following parameters: inlet, outlet positions, solid square positions, thermal coefficient λ, amplitude ratio ɛ, phase deviation ϕ and the solid square size on the thermo-convective flows. The Richardson number is varied from 0 to 40, the Reynolds and Prandtl numbers are fixed respectively at 100 and 0.71. To quantify the heat transfer of the solid block and to get closer to real conditions, we have developed a modification based on the evaluation of the Nusselt number using the average temperature in the cavity, unlike previous works which used the input temperature. As results, the sinusoidal temperature at the right wall gives higher heat transfer enhancement. The variation of the phase deviation and amplitude ratio have a slightly effect on the average fluid temperature and average Nusselt at the right wall and at the square solid.