Plenum cable

[bcyoung]

Is plenum cable needed in a building where there is no ceiling and the building has 50 Ton RTU's? The RTU's have duct work that extends though the roof into the building about 10' on supply side and the same on the return side. Would this setup be considered environmental air? Article 800&300

 

[Lcdrwalker]

A plenum is a dedicated area for the handling of enviormental air. In my opinion, the area in the ductwork would be a plenum but the entire building would not be.

 

[DUCKMAN]

Other Space

Other Space

Pleanum cable is needed in what is called "an other space for environmental air" 2008 NEC 300.22(C) states that an other space "does not include habitable rooms or areas of buildings, the prime purpose of which is not air handling".

So in short, the cable does not need to be plenum, if installed in an open ceiling.