New here and looking for your sage advice.

Our home is a one story 1949 ranch. I'm installing Panasonic ceiling fans in both bathrooms and have run into a snag...

I'd like to run the 4" duct to the exterior wall (not the roof). This is about a 6 foot run. But we have hipped roofs and the height between the ceiling and the roof is about 2" at the exterior wall.

I stopped by our local HVAC shop today and they didn't have much. I guess I could fabricate something myself that would include a 4" duct coupled to a thin rectangular duct. But I doubt that I'm the first person with this problem. I'm also considering using 4" PVC, use a Y to divide the line into 2 lines and reduce both lines to 2" to get through the wall. I run the risk of neither being all that pretty. Any ideas? Ideally, I'd like to have a louvered vent, but that seems highly unlikely right now.