My basement bathroom needs a fan. There is a window in the middle of its exterior wall. please refer to the photo. There is no way to make the duct outlet "3ft away from any openings of this house" if the duct goes forward and terminates on the exterior siding. The left of the bathroom is stair. So we cannot go left and then go forward. On the right side there are many drain pipes. It is almost impossible to go right and then turn forward. BTW, the height of the joist is about 9". It seems drill a 4" hole is not a valid option. Goes backward is possible and there is an existing exit outlet for old dryer which was moved to other place. But there is about 30' distance from the bathroom to that outlet. Just wondering is it possible to satisfy that 3ft requirement with the run outside the siding? For example let the duct turn up outside the wall and run 3ft. But how about louvers or damper? Damper may be necessary and louvers can be replaces with screen I think. 3 yrs ago the plumber installed a new gas boiler for us in the basement. The exhaust and fresh air PVC pipe both run up about 3 ft outside the building. Both have a "TEE" at the end. Do you think it is a valid option to borrow the same idea to bathroom fan exhaust?