This work presents the modeling and control of the temperature of a CSTR polymerization reactor connected to a semi-flooded horizontal condenser. The objectives of this work were to evaluate the cooling potential and the development of different algorithms to control the reactor temperature where bulk polymerization reactions take place via styrene free radicals. The control algorithms studied were classic PI, long-range predictive GPC and predictive-adaptive STGPC (GPC connected to the identification algorithm 'RLS'). The results obtained here show that the system provides quick, efficient and highly competitive refrigeration compared with other systems when this system is associated with a control algorithm which adapts perfectly to its dynamics characteristics. The new approach presented in this work, which associates the system 'CSTR + semi-flodded horizontal condenser' to the control algorithm (GPC and STGPC), makes the process highly competitive regarding refrigeration and performance.