A computational analysis of convective energy transport of water-based nanosuspension having variable thermal properties has been performed using finite difference method. The considered square cavity includes cold vertical walls and adiabatic horizontal boundaries. The local heater of periodic thermal production is placed on the lower border of the domain. The working fluid is water with copper oxide nanoparticles of low concentration. Control differential equations with initial and boundary conditions have been written using non-dimensional stream function, vorticity and temperature. The resulting nonlinear partial differential equations with associated boundary conditions are solved using the finite difference methodology on a uniform calculation mesh. The analyzed control parameters including volumetric heat generation frequency, initial fraction of nanoparticles, heater location and time have been studied. The physics of the problem is well-explored for the embedded material parameters through tables and graphs. The obtained data have shown that the volumetric thermal production frequency of the source and the initial concentration of nanoparticles have the greatest influence on the heat transfer performance. The energy source temperature can be reduced by up to 20% by varying the characteristics of the source and nanosuspension.