I may be adventuring into the realm of a mini-warehouse mining setup... i found a business park near me that has semi-decent 398sqft mini units for $298/month... they are already wired to some degree.. but they are limited to 220v @ 100amps....
Only issue keeping me to signing today and jumping onboard is the unknown of how to cool inside of such a tight space.. ive been told the doors cant be modified at all, but the inside is allowed to be modified as long as i return it back to how it is now when i leave... so im able to remove one of the sheets of plywood and place some sort of vent if i want in the ceiling.. the rafters are hollow between all the units and the roof has gutter ventilation only tho..... the rollup door is pretty loose and with locking the unit via the locking mechanisim, there is enough space to place about 2-2 1/2 inches under the rollup door in movement, so i could lock the door from the inside and keep wood wedged under it to allow somewhat of ventilation across the bottom....
Anyone on here have any experience in regards to this type of setup?
Having a small area actually makes it easier, because it makes for a smaller volume of air, but just having a door that is slightly open won't be enough (not to mention that this is very insecure).
The key is going to be moving enough air - cooling the air isn't really necessary unless you're dealing with temperatures well above 100F on a regular basis. If you're using open air rigs, you'll need fans capable of displacing all the air in the unit (~4000 cubic feet depending on ceiling height) a few times a minute to keep temperatures steady. I'm no expert, but this doesn't sound like you're going to be able to easily vent that much air safely to the outside (not just into the ceiling - it will build up if there isn't good ventilation out of the roof. If you use enclosed rigs, you could create hot/cold aisles, which drastically reduces the amount of air that you'll need to move.
220v @ 100 amps will still give you about 18kW of power to play with (technically 22, but you should avoid maxing it out in order to accommodate spikes and other fluctuations), which would be roughly 15-20 rigs depending on their configuration. You'll probably be spending at least 1kW on fans, if not more, so keep that in mind when budgeting your power.
I'm running 4 rigs in my garage, enclosed in a fairly small area (~20 cu ft), with a 3500CFM exhaust fan directly to the outside, and a 6" intake vent feeding fresh air. It's massively overkill since even with inefficient sealing it's refreshing the entire volume of air almost once a second, but even when dealing with 100F intake air, my GPU temps have been completely stable, with no more than a 1-2 degree fluctuation.
I've looked into getting a dedicated space as well, but the only way I can justify the extra monthly expense vs home hosting is if I can densely pack the unit - so I'd want at least 200A service (preferably 400A total) for a 400 sq ft space. Otherwise, it's simpler and cheaper to just use my existing electrical service and ventilation options.