We have recently been asked to install a critical panel feeder in a health care facility. Current conditions are extremely tight and I had to look @ the only clear route vertically up 3 floors. Is there anything that prohibits us to install the conduit in the stairwell, running in the same manner of the sprinker riser? It is not a common practice, but our options are limited. FYI, its a 1" EMT conduit @ 480V.