Hey doc thanks for the detailed help I will definitely be putting your rigid ducting input to use and will be running as much of the ducting I can above the room in between the ceiling joists I really like the idea of using cooler air to each intake of the air cooled hoods and I actually thought about doing so already but being how far north I am and In a basement our winters get very cold and also I would be to worried having the water and condensation running in my ducting from the only basement window I have and cause some serious problems so not ideal in my climate area, but I wI'll be running separate intakes to each and exhausting elsewhere in the home as extremely low cost heating method for the winter months... as far as the co2 goes I won't have to worry about that as of yet because I'm not running any to start and probably won't untill i go completely sealed and have a mini split installed
No problem man. The condensation issue can be reduced with insulated ducting--but what what I would do is add an dampner to bring mix warmer room air with the cooler outdoor air. Connected to a thermostat...would make it an automatic dampner.
BTW, the fans pulling the cool air through my light fixtures are located in my attic--no smell, no noise, & no heat to return back to my work area.
Good luck!