Riser Cable or Plenum cable in an interstitial space

[jakeparsons03]

We have electricians who want to run control wire from a device back to the control panel by taking conduit up to an interstitial space then free-air running it back above a control panel and dropping it in conduit to the panel. The interstitial space is technically not a plenum as while it has Make Up Air units, they are piped to the outside and to the occupied space. There are exhaust fans on this level though. Do I need plenum cable or would riser cable work here.

I get the feeling that this is a gray area and it would depend on how your inspector is feeling that day.

 

[hbiss]

If the space is used to convey air, whether heating/cooling or ventilation, it is considered an air handling or plenum space. Any cable run in that space must be plenum rated.

-Hal