I have a basement bathroom basically smack dab in the middle of the basement. The joists run from front-to-back of house. So going out either side is not an option. Going out the front is not an option because I will hit a slab porch. So my ways out are back or up.
Going up entails going 4 feet doing a 90 up and then out the attic. Going out the back - there is already duct work in the joist run the fan is on. It is an unfinished laundry/storage room and would be about 15 feet total.
So I guess my options are go under duct work (sticking below joist a couple inches but still 7 feet up) and out back, do a couple 90s to move to joist over (going under joist temporarily then back up) and out the back, or going 5 feet over then 90 through the main floor then out the attic.
The attic would be a long run - 5 feet, plus 10 feet to get to attic, plus 15 feet to get to soffit. To the back of the house would be 15-20 feet total.
Also I have thought about buying one of those no vent out machines that slowly releases humidity to laundry area. The basement/house is dry and could use moisture. Anything is in play!