This Might help Strive. I do this with my fish tank. And With my 400 closet I use for popping new gear.
I bought this bathroom fan it is super quite and moves a decent amount of air It has been running 10 hours a day for like 5 years. the only thing Ive had to ever do is clean the fan blades once. Mount it at the top of the tent and blow it ware ever you like. It might be enough to ware you can atleast let your central air shut off some save you on your bill.
It just enough to slightly create a vacuum with everything closed and removing the air from the top will cause a slight draw at the top and ever so slightly removing the heat. I know I do this with a 400 bare bulb.
And the fish tank is 3x250 bare bulb 2x96 watt vho's and some led's so Im sure it would help with your closed hood I would think.
If You can get the air drawn in to only come from the bottom it will draw fresh c02 up and through your canopy as well. And Im sure your know what fresh co2 will do.
Another thing is to tap an ac vent to draw your air incoming air from so even when your central air is off that evaporator is still cold for some time so You will draw cool air without your unit even running.
Just a few things Ive done over the years to deal with high bills and the brutal heat we have to deal with.
