Placement of CO2 sensors in a stadium bowl?

Chris, I would discuss it with your mechanical engineer and have them make a sensible proposal that addresses CO2 concentrations in the breathing zone. Then, present that to GBCI with a narrative explaining how it does the best possible job of meeting the credit intent and requirements. Then, hope for the best.Sorry to not be of more help on the technical details, but it seems like a question for an engineer.

Chris, I am curious on your final resolution for your project applying CO2 sensors in the return air ducts for the stadium bowl arena area? I have a similar project with challenges of locating the CO2 sensors 3-6' AFF in the arena seating area and have not found specific Interpretations or Addendas allowing space exemptions for this building type and credit requirement. I'm sure we could all benefit from any follow-up or GBCI reviewer feedback on how your project attempted this credit based on your challenge described above. Thank you!

Hi Chris,
You should look at mounting the sensors in the breezeway between the arena area and the surrounding concourse. It should be easy enough to mount it there. I suggest you look at one of the recessed sensors so that it doesn't get hit or in the way of the folks as they going in and out.
As an aside, since CO2 is a gas it's going to pretty quickly equalize throughout the entire space. The reason for keeping it down at the breathing level is to avoid it getting installed where it might be in the supply airstream thus giving you a lower reading than in the well-mixed seating area. Make sense?
Good luck and let us know what you end doing and how it works.
Best regards,
John

Hello, does anyone have any updates or additional information on this topic? - thank you!

CO2 sensors are not a prerequisite. 

CO2 sensors are a credit, more specifically "EQc Enhanced IAQ Strategies - Option 2, C. carbon dioxide monitoring"

The title of this post is mis-leading.

not all credits are a good fit for all projects.