I live in a 6 year old condo. My wife and I have always thought that the HVAC system never seemed to work all that well in either heat or cooling mode (you have to crank temp. setpoints up/down excessively). I checked the burners in the winter and refrig. system in the summer but everything has always checked out KO. Not too long ago, I opened up a 4"x4" hole in the ceiling in our lower level to fish some alarm cable through the ceiling. While I was working, the blower came on and all the drywall dust that I had just created was blown through the hole directly into my face. Suddenly, it ocurred to me that the problem may be due to a break in one (or more) of the duct joints. The problem is, the duct work is installed above our lower level ceiling (drywall) and completely hidden. Plumbers often use cameras mounted on long, flexible cables to check out u/g sewers, pipes, etc. Is there any type of similar device that an HVAC contractor/tech could fish into the ductwork to determine if (and perhaps where) we have a break in our system, precluding the need to destroy our entire lower level ceiling?

Thanks in advance,