The Replacement Fan Blade # BVC0466 and Replacement 12V DC Motor # BVD0218-00 will vent air out of your bathroom once it is installed on your Ventline V2399 unit. I have attached a picture of how this is installed for you to reference.
If you are wanting to use a vent that has the option to push air out or pull it in then I recommend using the Fan-Tastic Vent Roof Vent # FV801250 which operates via 12V, has the reversible function, and uses a manual knob to lift the cover. A review video... view full answer...