gas piping in a plenum - 404.1 IFGC

[syarn]

are you allowed to run gas piping in a plenum (space above a drop ceiling)?

any one have pdf copy of 2003 IFGC commentary section 404.1 that clarifies plenum from circulating air duct?

 

[civilperson]

yes.

 

[sensis]

piping or tubing may not be installed in a heating or ventilating plenum, duct or shaft, except it may be installed in a false ceiling space including one used as a return air plenum of a central warm air or air conditioned system.