Uh... don't listen to this person please. Co2 is a must in a totally sealed room. In any vented room, the co2 is naturally replenished to some degree. In a sealed room it absolutely is not unless you intervene with Co2 supplimentation. if you want the benefits of sealed aggriculture you have to do it right, and not skip any steps.
Other supporters of sealed aggriculture seem to really enjoy the mini-split AC units, they work wonders. 12000btu is ok, but it might not be enough with your burner going (if you are using a burner). They say it's around 3000-3500 btu per 1k light without a burner, and 4k+ per light with one. That puts you at exactly 12000, and keep in mind AC's do not run at 100% efficiency! Just a thought.
I'm gonna have to agree with stillcantroll. High levels of C02 in a properly balanced room with quality correct feeding will yield you a much larger harvest. C02 is cheap to supply and the equipment will pay for itself after the first run. If the room is sealed you MUST supplement C02!
As a Controlled Environment Agriculturist (CEA) I've played with several cooling methods. I currently run a mini-split system. It's an upgrade from portable AC's. The portables needed intake and exhaust lines. Intakes needed to be sealed off from pest and exhaust needed to be treated with a scrubber. The duct work coming and going, though looked impressive, was still a pain in the ass. The mini-split eliminated ALL my duct work and cools a lot more efficient then the portable.The mini's are expensive and need to be match perfectly to the heat load. Also, I find the mini splits temperature swings a bit more up and down which isn't good for C02 absorption rates.
My next room design will incorporate a large chiller with dual insulated reserviors (5 ton), ice boxes every other 1000 watt light, and air handler system to act as an AC and dehumidifier. Water cooled C02 burner and a reservoir chilling coil to each res.
I'm switching over to the water chiller method because chillers are even more efficient then AC's (40%) and far easier to install then mini-splits, not requiring an HVAC guy to charge or vacuum pump lines.
May cost more up front but the savings in electricity will add up fast. Also, saves me the security risk of having an HVAC tech on premise. Plus, the water cooled systems keep a very nice precise temp, with programing available for separate day and night temps. Water cooled systems also can use city water and a drain to waste bypass if chiller ever burns out.
Sounds very exciting to be upgrading your room. I wish you the best.
