I do alot of work in Washington and Baltimore, and I know the feeling, most ductwork runs in the elevator shafts, and access is very limited if at all, I have seen many places where gaining access would involve much expense and in some cases if it is possible it is only at the top and limited, on the few ocasions I have gotten access I was cleaning it for the first time ever in many many years.
What do you do when you open up a 12 story duct that has never been cleaned since it was installed 12, 15 yrs ago, your only access is at the top, you can't access at the bottom of the duct before the horizontal run, if you have water leaks, it will leak into Goverment offices, or in one case a jewelry store, where even if I got accees after hours I can't get into the duct without removing a large part of the ceiling first.
It is not that I don't want to do the work, it is that no one wants to pay for the work to be done. with no axaggeration if someone/agency started to require NFPA 96 to be complied with, 65 to 75% of restuarants in DC would have to be closed down. Last week I went to look a Mcdonalds in a shopping Mall in the northern Virginia area, three hoods 75 ft. of horizontal duct, old duct that was in use when the location was a Roy Rogers 15yrs never cleaned, Access can be installed in the ductwork in two places and then only on the bottom of the ductwork without removing AC/heating duct first, then the duct continues ouside under a parking garage to the fan that is mounted hanging from the ceiling, again the ductwork is sandwiched between two other
ducts, can only install access on the bottom. The fan does have an access in it, but then another duct is attached to the fan and continues horizontally 50ft to exhaust the air out from under the parking garage, not one access, the screen on the end of the duct was almost clogged shut, I climbed up and scraped it open because I felt sorry for the owner who told me that the store had been open for over two years and she can't get anyone to clean it, no one will touch it. She is squabling with corporate McDonalds for selling her this headache. I am trying to stay out of the middle, I did give her a letter stating the problems that she forwarded to whoever, but have gotton no response so far.
The one time I got Corporate and the building owner to split the cost of cleaning, we spent two nights running a duct spinner up and down a 12 story duct, installed access at the top in a fire wall and then in the grease duct, could only get access at the top and at the bottom, well anyway after that a new owner operator took over the store and told me I was crazy if I thought they where going to pay that much money to get the exhaust cleaned, he had someone who would do it for $250, I'm sure they clean hoods and fan only. I sent a certified letter to the owner operator, the property management co, and the building owner. Just to make sure I could in no way be held liable for any future problems.
Sorry for rambling on but I read in an earlier post that getting access to I think a 5 story duct should be no problem, sorry if that may simplifies what was actually posted, anymore I just go look at these places show them whats wrong give them a price that usually drops their eyes out of there sockets and move on, and this seems to be the norm for me when I get close the the city and in some cases outside of it.