The use of a scaled model can be an effective technique to predict ventilation performance of full-scale prototypes. Many criteria have been proposed to predict the behavior of airflow in a scale model and a prototype. Because of inconsistent results of proposed similarity criteria, more validation work is needed to clarify the conflicts. Experiments to study airflow similarity in ceiling slot-ventilated agricultural enclosures using different similarity criteria were conducted on two scale models. The studies focused on the Reynolds number (Re) and inlet jet momentum ratio (Rm) as the similitude criteria for isothermal airflow. The experimental results offer better agreement using Rm as opposed to Re as the similitude criterion for isothermal airflow pattern control.