First of all, you'll never get the temps in a cab below the ambient room temps without an active cooling system (like an AC, Swamp cooler, etc) so 82 is the lowest it will get in there.
I think you're ventilation is backwards. You should have the 6" pulling air through the scrubber, the hood, then out of the cab and use the 4" as an intake fan. Another option if the 6" is too powerful for your scrubber, would be to setup the 6" to air cool the light only via a closed loop (dedicated duct to light > fan > outside cab)...and use the 4" to vent the cab via the Can9000 with passive intakes.
The way your system is currently setup, it will create positive pressure in the cab which will lead to odor leaks.
What are the temps in the cab?
I think you're ventilation is backwards. You should have the 6" pulling air through the scrubber, the hood, then out of the cab and use the 4" as an intake fan. Another option if the 6" is too powerful for your scrubber, would be to setup the 6" to air cool the light only via a closed loop (dedicated duct to light > fan > outside cab)...and use the 4" to vent the cab via the Can9000 with passive intakes.
The way your system is currently setup, it will create positive pressure in the cab which will lead to odor leaks.
What are the temps in the cab?
