ent in cold air returns

[Cleveland Apprentice]

Is ENT (smurf tubing) permitted in cold air returns in dwelling units?

 

[don_resqcapt19]

See 300.22. Is this an actual duct or is it an enclosed stud or joist space?

 

[Cleveland Apprentice]

this would be actual joist space. I will check 300.22, thank you.

 

[Dennis Alwon]

this would be actual joist space. I will check 300.22, thank you.

You can traverse the joist space- run perpendicular to it but you cannot run parallel to it with ent. You can even traverse the pan joist with nm cable. Sleeve it in emt and then your are good.

 

[Cleveland Apprentice]

Thanks Dennis, the ent I'm running will be running parallel in the cold air return joist for about 12" to 18" then 90's out of the joist space. I'm using this as a chase to pull catv later. I hope the 12" to 18" parallel is not a big deal and pass inspection. If not, I'll just remove it and go buy 1" fmc.

 

[kwired]

With most construction today using engineered "I" joists sometimes I will pan off the "I", leaving a space that is not within the environmental air handling space, if I must run something parallel to the joist.