Piper Dakota overhead vent leaking air

[hummerboy2482]

Piper Dakota overhead vent leaking cold air inside cabin. What would be the best way to minimize the cold air coming in is there something I can do to the outside vent on the vertical tail is there anything out there to close or cover it reducing the fresh air coming inside during the winter months thanks for all the input

 

[sanjiv]

 

[Orest @ CYFD]