I hope someone from this excellent group can assist me with this problem. We have a cold room on the second floor of our house. We have a forced air, natural gas heating system and there is only one vent in the room. There seems to be very little airflow through the vent. I've checked down the duct to see if there is any restriction and there doesn't seem to be any problem.. I suspect that the duct is separated somewhere between the furnace and the supply vent... The problem is that the vent is inside the ceiling and walls for it's entire run.

My question is: what would be the easiest way to inspect this duct. It has at least 2 or 3 offsets in it before it makes it's way back to the furnace so I can't just lower a camera in there.

Thanks for all replies.

Peter H