I'm starting to run some low voltage wire for motion detectors, door/other sensors, network, cable TV, etc. throughout my 30 year old home. There's a very convenient cold air return from my family room on the first floor to the rather large furnace room in the basement where my servers are setup that I'd like to use for some of the cable. The rest of the basement is finished without easy access to the floor above. The cold air return is formed by the joists between the floor and ceiling with no actual metal duct work and is actually open at the end to the basement itself (as well as to the HVAC air return). Is plenum rated cable really necessary here? Would non-plenum cable likely be a code violation, dangerous or cause problems with insurance if there were a fire at some point?
Thanks for any advice.
Thanks for any advice.