The only details I find are an open pit with the exhaust fan pulling from the center to one side , no baffles or other obvious ways to balance the air flow.
Primitive must work ok, I stopped at the Nova Verta distributor and he said theirs have no balancing mechanism in either the inlet or exhaust .
Having worked in the trades I assumed that a booth would have a balanced air flow similar to doing T&B on the ventilation systems in commercial buildings.
*** u ME d, my first mistake.
I think I will make my pit tunable with a minimum of 3 zones, front, center, and rear.
The cost to pour the pit is only a few hundred dollars more than just a floor, so why not!
The grating will cost a bit, but some 2x6's will cover it until grating is procured.
Water in the pit is not a concern, there should never be any. If so then a small sump pump to move it outside will work fine. ( just have to remember to grade the floor of the pit to a sump, thanks for the tip)
Would like to use squirrel cage fans instead of propeller fans, quiter and cheaper per cfm to run according to the "fan experts".
Until all the parts are acquired, it will just be a 15x28 storage shed, lol.