The work models and simulates fire growth in a closed room. It examines the effect of various airflow rates of mechanical ventilation on wall and ceiling temperatures, Heat Release Rate, oxygen and carbon dioxide rates when smoke/fire is detected. The objective of the simulation is to find a way to control the temperature, fire growth and gas rates in the room until fire fighters have control of the situation. The model assumes that the ventilators are continuously operating. The results of the simulation show that there is a certain airflow rate for the mechanical ventilators that achieves the goal, thus avoiding fire breakout. The modeling and simulation is carried by CFAST which is a zone model tool for fire modeling and simulation.