The optimization of production processes has great importance in the world due to the development and advancement. In order to evaluate the productive performance in poultry production, it becomes necessary the indoor environmental adequacy of the poultry buildings by technologies that attend the requirements of thermal comfort with major energy efficiency. This study evaluated the thermal environment of a domestic shed of negative pressure tunnel type, during the first growth phase of broilers. The evaluation of the thermal behavior model during this period was made using the computational fluid dynamics (CFD). The computational model proved to be an effective tool for understanding and improving of bioclimatic designs of indoor environments to create this kind of sheds.