Flexible Ducting. If it isn’t practicable to cut a hole where you you wish to mount an exhaust fan, a range of flexible ducting is available which can house the fan. The air can then be channelled through the ducting, to any room outlet.
A selection of adaptors are also available. Ducting Adapters work well for example when needing to use a different sized fan to your current ducting (or visa versa).
Image may differ to stock type currently available. (metal / plastic)