Hey HydroDawg. Thanks for stopping by. Glad to help. Sounds like you are ready to step it up a notch. Congrats man. Always fun when you grow BIG!!!
Just a couple suggestions and feedback and then i'll get working on a plan depending on your answers.
Is there anyway you could mount that minisplit on the North or East walls? You can put the coondensor anywhere outside but I think that West wall is you best bet for plants and lighting. Would be ideal if you could have the a/c on the East wall blowing at the plants. Also more efficient. Let me know.
I'm gonna make some suggestions in regards to your lighting. First off, you have plenty of cooling with a 2 ton a/c unit for 3 lights. It's up to you but I would get a 3rd light ad maybe a 4th in the future. If you have no electrical issues and are looking to expand then you have plenty of room in there for up to 4; an possibly 5; lights. For now I would get the 3rd light if you are thinking about it anyway. If you are going to get the 3rd light then let me know so that I can make the plan accordingly.
Something to think about...with only a 7' ceiling you have very limited plant height to work with using those 1000w lights. Your light will take up a foot and then you can't have plants any closer than a foot. Plus you DWC buckets will use 14-18". So you are looking at 3'6" plants max I think. You could add 6" to that by running your ballasts dimmed to 600w. If you have dimmable ballasts then you always run the appropriate bulb for the setting. Don't dim a 1000w bulb; dim your ballast and run a 600w bulb. Just something to think about.
How tall do you normally grow your plants? Do you make them bushy as well? Just trying to get a general idea as to the footprint you will need for that system. Sounds like you grow fairly large plants and I think you might need a 3rd light to cover the distance of 9 plants.
If you are bringing a subpanel into that room then I would make some changes to your electrical setup. Are you running the a/c off that subpanel? What kind of ballasts do you have? I imagine that the a/c runs on 240v. If you have ballasts that can be wired for 240v as well then I would get the cords and wire then that way. The amount of money you'll save on cable and the subpanel will more than pay for the 240v cords. If you go that route you won't need a 100amp subpanel anymore. You will be fine with a 60amp panel as your lights will only be drawing about 10-15amps total and your a/c would draw another 10amps. That would leave you safely 20amps for other equipment. Either way, when you get into 3-4 light grows Irecommend light controller boxes. They are the safest way to run multiple lights. Basically you would hardwire the box directly from your subpanel. Then you would plug the ballasts into the box. You can get the box with a built in timer or just use any timer that you have. The box runs the power for the lights on a seperate circuit that is hardwired to your subpanel. You still need to power the relays of the box and the timer. This is why the boxes have a "trigger cord" which it a 120v plug that does't use any more electricity than it takes to flip a relay. You would then plug this trigger cord into a High Temp/Hot Strike box which is plugged into the wall outlet or into your timmer if you choose to use that. These high temp boxes basically prevent your lights from Hot Restrikes after a power failure or surge.The box will make your lights wait 10 minutes before coming back on. Will save your bulbs and increase their lifespan. They also have thermostates and probes to shut your lights off in the event that something happens and your room reaches a temperature setpoint. Usually 90-95 degrees and you want to shut it down. As soon as temps drop back down the box with then flip the relays on your light controller and turn the lamps back on. These boxes ar well worth the $70 they cost. Also; having a light controller is very efficient and safe.
If you set it up this way then all you would need were 4 outlets in the room on 2 20amp breakers. 20amps for 2 outlets is more than enough. You won't need anymore power than that for the additional equipment you will put in there. A dehumidifier or a chiller is only going to use 5 amps.
I would recommend a small dehumidifier. Minisplit units are great at dehumidifying but like all a/c's they have to be cooling to actually dehumidify. During the dark cycle most a/c units don't work as often and therefore do not dehumidify as much. Sometimes this can lead to humidity spikes. Something to think about. Although, if you are running your lights at night and during the day it gets to 90+ outside maybe your a/c will be running enough to keep the humidity in check. I would keep an eye on it.
$550 a roll? Damn bro. I would save your money man. Get some silicone and caulk and seal the room up nicely. If you have exposed joists or framing then hang some plywood or drywall. Then put duct insulation wrap on all of the walls (
http://www.ecofoil.com/Applications/Residential-Insulation/R-8-HVAC-Duct-Wrap-Insulation). Not only is it a great reflective material but also acts as insulation for your room which will make your a/c much more efficient. That with a good carbon filter and you will be fine. I promise. Plus it will save you a ton of money. I would recommend the CAN 75 filter and a good 8" high output fan. Buy CAN or Vortex cause most of the other fans don't come close to their advertised CFM ratings.
I'm all for sealed grow environments. You can still seal your room but exhaust your lights though. If it get's hot outside I think you'll be surprised how much your a/c is going to be running; especially with 3,000w of lighting. 1000w lights can create a need for 8,000btu of cooling all by themselves if they are not vented from the room. So you could easily find yourself in a situation where your a/c is running the whole time the lights are on. If it is a possibility I would just create a closed loop on your lights. Pull air from outside of the room through the lights and then exhaust it back out of the room. You can seal this loop by using insulated ducting and flashing tape or foil tape to completely seal your hoods. You won't have any odor issues with the exhausting air this way. The other option would be to pull air from your room through a carbon filter and then exhaust that outside. I would still use the CAN 75 to scrub the air in the room and just get a small CAN 33 for the intake side of your lights. Either way you aren't going to have ANY issues with odor. Plus your a/c will work much more efficiently and last a lot longer. I know you said "NO" vents but I just wanted to throw that out there.
Just a suggestin but try and put your ballasts in a room that is cooled by the house or with a wall fan mounted to blow on them. Electronics like to run in cool temps. They can heat up really fast (especially if that chiller is in the room with them) and this can lead to shortened usage times and other problems.
Your specific questions:
1. You are not being naive. You ould fill that room with 4-5 lights and all the plants you want. If it is sealed correctly (vented hoods or not) and you have an appropriate filter/fan then you won't have any issues with odor outside.
2. You either create positive, negative, or neutral air pressure in your room with the ventilation setup that you have. If you are bringing air into your room from outside of that space then you hav positive pressure in the room and the air will look for places to get out as new air comes in; usually under doors or through cracks and windows. If you are pulling air out of the room (like i described with the filter on your lights and exhausting the air outside) then you have created negative pressure in your room. This is ideal for most growers because you are controlling the odor of the exhausting air and by creating negative pressure all of the places where air can move in and out are sucking air into the room. That way no air is escaping that is not passed over a filter. Keeps smells from pouring out cracks and under doors. The way you have it setup is neutral air pressure. You are neither exhausting air from anywhere or intaking air. The problem with neutral pressure is that you can not control the intake or exhaust of the air. That will be determined by the airflow and the pressure of the rooms around you. If the other side of your door has negative pressure than it will pull air from your room.
3. I really think you are going to need another light. If at all possible I would run them at 600w with 600w bulbs. If not I just don't see how you can fit 9 plants in a row under a 10' span. A 1000w lights basically has a 5x5 footprint; even with those hoods. Maybe 6-12" more if they are side by side. Still, that would mean you really only have about 14" width for each plant. I would put them on the West wall. At 13' long that would be perfect for 3 lights and would also keep them in a straight line which is always more efficient for ducting. If that is a problem then I would do an "L" shape between the West & North walls or the North & East walls. If you go with 2 lights fo now then you can put them on either the East or the West wall. I just don't like having my lights right in front of the door to the room.
4. I think so. You could get more grow sites if you add another light. You say that your system is only 100" long but that must mean you are growing some SMALL plants man. With that length you are only giving your plants like 8" of width. A 12" plant needs that much width. Your bucketsa have to be bigger than that? If so then you could definitely get away with 18 under the 2 lights. I would say go with 3 and maximize the amount of buckets that you can fit in there. Maybe 22-26. Grow some bushy plants. Maybe LST and TOP them in veg. Keep them short but with multiple colas.
5. If you wanna grow "as much as you can" then get 2 600w ballasts nd create and "L" shape between the West & North walls. You can fit maybe 26-30 buckets in that space. Probably would want to get a bigger reservoir or run dual reservoirs. If you ran dual reservoirs you could do a perpetual cycle which would allow you to harvest every month instead of every other month. I'm just fantasizing for you right there. LOL!!! Shit, you could get up to 6 lights in that room no problem and still have plenty of room. Get 40-50 buckets going....no I'm getting crazy!
Well, I think that's all I have to say on that. Probably just gave myself arthritis. Let me know what you think.