between the first end 52 a 52 f and the second end 54 a 54 f is not entirely sufficient to deflect airflow the deflector ribs 50 a 50 f can be arranged in any suitable manner for example the deflector ribs 50 a 50 f can be arranged such that they extend lengthwise between the first end 52 a 52 f and the second end 54 a 54 f in a direction generally perpendicular to a main airflow stream a as illustrated in fig2 for example the deflector ribs 50 a 50 f can be arranged in any suitable orientation relative to one another in order to extend generally perpendicular to the main airflow stream a such as along a curved line b which is illustrated in fig2 and extends between the heater core 14 and the evaporator 12 first deflector rib 50 a is arranged closest to the heater core 14 furthest from the evaporator 12 and furthest from the base 44 of the hvac case 42 sixth deflector rib 50 f is arranged furthest from the heater core 14 closest to the evaporator 12 and closest to the base 44 the deflector ribs 50 a 50 f can have varying lengths for example the fourth deflector rib 50 d can be shorter than the neighboring third and fifth deflector ribs 50 c and 50 e the deflector ribs 50 a 50 f are generally arranged staggered or offset with respect to each other along the curved line b for example the third deflector rib 50 c.