The heat losses by convection from the collector tube of a trough collector to the ambient are analyzed. The strategy to reduce such losses is by using a vacuum glass tube covering the collector tube. Since the maintaining of this vacuum state is difficult, beside the high cost and easily broken off the glass tube, another strategy presented in this paper. The strategy based on reducing the overall convection heat transfer by the use of guides made of metal, which effect on the process of heat transfer. The guides put in front of the collector as a half circle with different dimensions, and each one analyzed numerically by using 4.4 COMSOL Multiphysics program. The analysis include the streamlines behavior, temperature distribution, and average Nusselt number. The minimum the Nusselt number obtained the best arrangement to use. The data show a decrement in heat transfer process due to that modification with different percentages.