If your going to do this setup properly especially to the magnitude your talking about, its best to plan and build for the harshest enviro conditions you could face (eg summer temps) and then have the systems in place to juggle everything in between. Passive ventilation setups will work fine but with the intensity of the DE's you can grab 5th gear and push the plants to the max. In order to do that your going to need to implement co2 injection. I had one burner in each room and it was more than sufficient. Bottles are for us basement guys, and the mondo facilities are using liquid co2 for the most part. You will want to have ventilation in place regardless to expel the co2 for lights off regardless...
You'll never truly know until you've got lights fired up and seen how each season impacts your environment. Obviously winter will greatly help counteract with the heat created in a sealed setup. With our ceiling height we had a huge area for the heat to rise rather than sitting on top of the canopy compared to say an 8-10' ceiling height. I believe the handlers were around $2500 each and then to install and charge the lines with coolant was another $500 each. Prices in CAD so half for that for you Americans lol. Nowadays the proper way is a good commercial unit with venting plums.
I have no experience with the commercial #-ton AC units so idk how they work for dehumidifying, but I loved having the handlers in that aspect. I had the condensation lines plumbed into the nutrient room going into 55 gallon drums to reclaim all that water which comes out the same as RO.
Bringing in cold air during the winter also creates problems with condensation issues from the massive flux in temps as well as humidity fluctuations.
I'm not saying that there isn't guys running big boy setups and doing passive. It's definitely doable, but if your going to invest in a Ferrari, you gotta buy the expensive tires. There's nothing better than having the systems in place to adjust your temps and humidity with the press of a button.3
When your talking about pulling massive weight, what's the extra $10k-$15k to dial in your environment controls...
Sorry for the novel. Im baked and have too much time on my hands.