I have an older home with two bathrooms with showers. Both bathrooms are intended (I guess) to be vented by the windows. I have installed an exhaust fan with a vent through the gable end of the house. I know the fan I put in has a backflow preventer. I was thinking of installing a vent in the second bathroom. If I install a new duct & exterior vent, they will lie right next to the existing set.
Can I add a T connection to the existing duct so I can vent both bathrooms through the same exterior vent?