Combining venting for two fart fans

[SteveoinBoulder]

I recently discovered two fart fans in an apartment building were venting into a stud bay. Don't you just love that?!

Anyway, I would like to properly vent them outside through the roof and I am thinking to connect them together (in the attic)and then send them through the roof in order not to have two roof penetrations. The new fart fans do you have a built-in damper which gives me some confidence I won't have an issue with blow back- but, I'm not really sure of the wisdom of this.

Can anyone illuminate or advise?

Thanks!

 

[Plumber69]

Dont think you can if they are both running at same time. One may not open