Need Exhaust / Odor Advice & Opinions for my stealth closet cabinet?

Greetings and Thanks for reading.

My closet cabinet is 4' wide, 2' deep, x 8' tall. It is separated into 2 individually sealed compartments. The top 1/3 is for veg. The bottom 2/3 is for flower.

I will be using 6,500K cfls in the top veg chamber and (1) 400W HPS light for flower chamber.

I will be using a 150 CFM CanFan exhaust and placing it in my attic. As of now my plan is to tap (3) duct lines off of that exhaust, each with its own damper. (1) will go to veg chamber. (1) will go to direct to HPS light hood, and (1) will go to the flower chamber.

I will cut air-intake holes at the bottom of each chamber.

This system will allow me to close the damper and intake to the flower chamber and run CO2 in a sealed system. While still allowing the fan to run 24/7 for the other (2) exhaust needs (HPS light and veg chamber).

What are your thoughts on this system?

Where shall I place a carbon scrubber in this system?

Overall, I am shooting for stealth. I believe the attic will hide the fan noise, but I hope the damper system is not too noisy. I also need to control odor 100%.

Thank You.

I finished the cabinet and it is operating quite well. I have a guest staying with me who has NO CLUE. I ended up using PVC for most of the exhaust ducts and valves. As I only have plants in the VEG chamber right now, the valves to the FLOWER chamber and the HPS light are closed, while the veg chamber valve remains open, with constant exhaust and fresh air intake. My temps and rh in the chamber are ideal thus far.

Does anyone have suggestions on how to cut down air noise when working with pvc pipes as exhaust???? There is some noise, but you can really only hear it at night when the house is dead silent. I plan on wrapping the pvc pipes with insulation, but is there anything else I can do?

I am still also looking for suggestions on where to place the scrubber in this system.

Thanks....I will post photos of this whole contraption shortly, so keep an eye out.