CO2 Piping within building

[SAK9]

Guys,

Is there any special precaution to be taken when CO2 piping is run in ceiling space which serve as return air plenums?
Do we need to put ina CO2 detection system ? Is it required throughout the length of the pipe?Is the pipe required to be double contained under any codes?

 

[imok2]

In my opinion any time you are using the ceiling as a return air plenum and any type foriegn substance can invade the space, such as you are suggesting, you should take precautions for detection if for no other reason but to protect the owner from liability.I don't know of any reglations concerning your particular situation.