A piezoelectric PVDF film is made to vibrate in HVAC air ducts and is excited between fin attached to it and the vortices shedding from the bluff obstacle. The bluff obstacle is placed ahead of the fin and the piezo-electric film arrangement. Maximum power output from the PVDF film, is achieved when input excitations from vortex shedding are iteratively modified to match the natural frequency of the film. The incoming airflow velocity is maintained in the range of 2.5-3 m/s. In the HVAC air duct, the output power is generated by utilizing various fin materials at an airflow speed in the range of 2.5-3 m/s. The resultant output power which could be used to power wireless sensors, is found to be in the range of 0.655* 〖10〗^(-9) W.