I am sure that all inspectors expierence this scenerio!!
There was a duct or flue running thru a closet in the middle of the house.
There was a chimney location at the East & West side of the house. The basement was finished and I wasnt sure what the vent was for.
I had my client go upstairs & start stomping on the floor. I located there nearest drop ceiling panel & located what was a supply vent. I felt like I was on the Poseidon when he was pounding & I located the vent. (See photo)
There was also a home made laundry chute. Safety issue with no doors.
This was an eisier find in the basment.
The poop pipe was a little more difficult.
It is an adventure to locate some of the homes systems. Any stories would from other inspectories would be fun to hear of your expierences.