House A/C duct to grow room or closet vent to grow room?

I'm trying to complete an inclosed growroom in my attic , and I'm at the venting portion of it. I am thinking that I can reroute a duct that is being used to push a/c to a vent in my closet to my grow room for intake air to make it easy to control temperature with the main thermostate in the house. Would this work better if I route from the closet vent to grow room? Or from a/c to growroom? Thank you for commenting in advance

I read a post on another forum whereby a guy did this in an attic grow. It was mainly so he was able to control the temp in his grow space in sub-freezing temps. He said it worked out very well at 1st but had some problems because he aimed the vent right at his plants. As long as you don't do anything of that magnitude you "should" be ok. Trial and error is the only way to learn, good luck!!!!

its possible but the smell might be an issue. especially when the AC kicks off....

Well I plan on using carbon scrubbers between intake and exaust positions... will that be enough?