New 10x10 Veg and Flower Combo

  • Thread starter meowkitty
  • Start date
  • Tagged users None
meowkitty

meowkitty

11
3
Hi all – first time poster here. I appreciate everyone’s commitment to making this the “go to” board for information sharing on our beloved practice. I’ve learned a ton through countless hours spent scouring this and other message boards to come up with a room design that will hopefully provide optimum conditions for growing….but I will leave it up to you, the experts, to be the judge. It’s a bit of a read so thanks in advance for taking the time.

Background:

I have a few grows under my belt, mostly outdoor but a few months ago bought a 4x4 tent and LED light and since then things have spiraled out of control. :) I am growing in a 13x30x9 foot workshop (metal building, un-insulated) on my property. The summer heat necessitated insulating the tent with ISO poly rigid insulation on all sides (essentially building a giant “cooler” for the tent and contents). Then I picked up an old 10K window AC off CL, built plenums and insulated flex ductwork into the tent/room on a closed loop. The exhaust of the AC also has a plenum and a 440cfm inline fan to push the air out of the workshop. At that point I figured I would add CO2, 30 pint dehumidifier and a CHHC-4 controller to maintain the environment. So it’s a self-contained, sealed environment at this point. Overall this setup works pretty well! The main problem it’s pretty energy intensive with the AC kicking on an off all the time. It’s oversized for such a small room. I figure a larger room with a mini split will be more efficient for, at least concerning AC usage. Additionally, with a 4x4 room, I don’t have any workspace (besides the workshop itself) or a decent environment to clone/veg/mother in. I could bring this into the house, but I have a preference to keep it all out in the workshop. So… I’d like a bigger, dedicated space.

Climate:

Outdoor climate where I live is often called the Mediterranean of the US. (aka: San Diego). Temperatures rarely exceed 90 degrees (but can reach over 100 a few days of the year) and generally stay in the 70-80s during the summer days and can get down into the 30s at night during the winter. Humidity is usually around 50%.

Design:

I grow for personal use with the occasional supply to a friend or two. As such I am looking to limit my ongoing operating costs (within reason) by doing this build with energy efficiency in mind. I would like to spend the money up front in hopes of achieving this.

I want to create a 10x10x8 sealed room split 5x10 for flower and 5x10 for veg. The overall room will be sealed with each room being more or less sealed from each other. Take a look at my renderings from Sketchup for more design details. Please forgive that the scale is off a bit.

front_GR.jpg top_GR.jpg veg_GR.jpg wrkshp_GR.jpg

Heat Management:

I would like the ability to vent both rooms into each other and independently (I know, it’s “not sealed if it has vents”), but hear me out! :) The plan is to install 6” automatic dampers on the intake of the veg and flower room with a Horti-control shroom filter to prevent the heebie-jeebies from getting in. For exhaust, each room will have a 6” carbon filter connected to a 440cfm inline fan connected via insulated ducting to the outside of the workshop. The exhaust fan in the veg room will run with a temp controlled switch. The same will occur for the flower room BUT only during the “night” period (actually day time). If the “night” period gets too warm for the fans I plan to have the setpoint of the AC just above the thermostat controlling the fans and auto dampers. For example if temps are between 75-80, exhaust and dampers operate. Once temps reach 81, the fans shut down and the dampers close, leaving the AC to do the work. I still need to figure out how to have only the ventilation or AC running at any one time (maybe the ventilation temp sensors would be located outside of workshop and measure ambient outdoor temp, or program a Raspberry PI?) During the “day” in flower, AC will manage heat and I’ll pump CO2 in. The exhaust fans will turn off, dampers will shut. I should be able to coordinate this with the built in AC timer and timers on the exhaust fans/dampers.

I would ideally like to use one AC unit for both rooms. I am planning on getting a 12k btu Mitsubishi Mr Slim 21 Seer, or something similar, to be located in the flower room. However if you think I should go for a dual zone unit to include in the veg room, I would like to hear about it. I was thinking about putting an exhaust fan between the flower and veg room with two 8” darkroom light baffles to pull cool(er) air from the flower room into the veg room, on hot days. This fan would operate via a temp controlled switch as well.

Construction:

2x4 framed, OSB exterior

R13 fiberglass or denim insulation

Drywall interior (or OSB) coated in elastomeric rubber roofing sealant for water proof reflectiveness

ISO R-10 Insulated floor on top of concrete slab

Dedicated electrical panel in workshop that has tons of capacity, including 220v already run. I will connect the mini-split to the 220v and have two dedicated 20amp circuits for lights, fans and dehumidifier.

Not sure about doors yet. I was thinking about an outswing 30” door for entrance into veg and a pocket door for flower room entrance to conserve space (but haven’t figured out how to seal that up yet so may end up with a standard door for it also).

Veg:

Clones, Veg and a couple of mothers-

T5 lighting

All Soil

4x4 tent with a shelving system (left unzipped)

Drying cabinet

Work table

RO system w 11 gallon tank

Control panel and CO2 tank

Intake: 6” auto damper w/ Horti-control shroom filter

Exhaust: 6” 440cfm fan with carbon filter

(2) 8” dark room baffles between flower and veg wall

6” intake fan from flower


Flower:

6-8 plants at one time –all soil (organic)

2 Mars 900 LED lights (I already own one)

30 pint dehumidifier, connected to hose (mostly for “night” dehum)

Oscillating fans

Mr Slim 12K btu mini split

CO2 injection

Intake: 6” auto damper w/ Horti-control shroom filter

Exhaust: 6” 440cfm fan with carbon filter

Thanks for hanging in there thus far. I promise I’m about to wrap it up! :)

My questions:

1. Will my ventilation/AC scheme produce the results I’m looking for? I would like to take advantage of the “nice” weather here and came up with this idea. However, if you think it’s too complicated or I won’t see much benefit from the extra effort and cost I’d love to hear it. I could always just seal the whole thing up and deal with spending more for electricity. May push me to go solar on the house.

2. In line with the previous question, should I plan on getting a dual zone mini split? If so should both sides be 12K given the room size (maybe too much, two 9k’s would be better or a mix?)

3. I’m pretty happy with the Mars II 900 watt LED light, but could be persuaded to move it to the veg room if you think a 600 watt HPS, aircooled, etc is better. May have to scale my electrical up. The LED is pretty energy efficient (relatively speaking), so like that idea.

4. If you have other ideas for more/better insulation, let me know. Does cheap and good exist here? The 1.5” R-10 ISO boards are $25 each, kinda spendy to do two layers throughout the box.

5. The budget for the project is in the $5K range with most of it being spent on the AC unit and install. I will install the compressor and condenser units and run the lines. Will have an HVAC tech hook it up and vacuum the system. I think this should cover it but let me know if I should plan for more (or less).

6. Should I plan for more electrical circuits or a subpanel?

Thanks for reading and any advice in advance!
 
FlyinJStable

FlyinJStable

2,518
263
I may be new but I feel I have some helpful input one
ONE: run the rooms at night take advantage of the cooler air and axe the ac in the veg then the only time you will need the ac hopefully is right at dusk to lower the temp prior to led ignition all lights put out some heat this is true.
TWO: Grow in hemp y COCO with act and feeding I started in RDWC and have grown in earth I like it all just found the control and simply put the lazy way as BOZO would say but its just my two cents
The Farm has a multitude of threads that show dirt coco o2 hell everything under the sun.
so Let me say welcome to the farm and
GET YOUR GROW ON
FlyJ
 
meowkitty

meowkitty

11
3
FlyinJ - thanks, good info. I agree I would like to ditch the AC in the veg room. I already run the lights at night and think it's a good policy for energy efficiency. Worst case scenario is I find that the veg room won't cool off and I need to add another unit later. Interesting perspective on the hemp y COCO. I will do some research, but it sounds like that may be the way to go!

Regarding the sealed/ventilated room strategy I wonder if this remote sensor digital thermostat would work to control the exhaust fans? I am thinking about putting the probe outdoors to measure ambient air temp. I could figure out what temp range works best to keep the inside of the room(s) within the ideal temp. Any thoughts on this idea?
 
FlyinJStable

FlyinJStable

2,518
263
I found without CO2 74-76 is best no more than 82
And if you use CO2 from what I understand 80 84 is average but that is based on information not personal exp as I have never used CO2
enjoy
Much Respect FlyJ
 
meowkitty

meowkitty

11
3
Ok, so I think one of my main questions I'm trying to answer is around ventilation and A/C.

I really want to build this room correctly the first time with the hopes of having a long-term, easy to maintain setup. For this I think it'll be good to include as much automation as possible. As such here is the idea I would like to hear your thoughts on:

Has anyone built a ventilation system that is controlled by either an environmental controller or an Arduino or Raspberry PI (with appropriate sensors of course) computer that:
  • Activates an auto damper and fan within a certain temp and/or humidity range and with different programs for day and night?
  • For example, in flower: outside temp between 70-80 degrees AND humidity is between 10-45% turn on fan/damper during the hours of 8am-8pm (plant night cycle). Otherwise turn off
  • Then: nighttime AC setpoint is 81 degrees and humidifier set to 46% (in case the temp gets too hot outside or the humidity gets too high). During 8pm-8am (plant day cycle) turn off ventilation system and only use A/C, dehumidifier and CO2 set to 78 degrees, 45% humidity and 1200ppm.
Basically this would allow for passive/active ventilation cooling when the outdoor conditions are correct and A/C when the outdoor temp/humidity is outside of the ideal range. Also during the "day" the room converts to a CGE, closed system.
 
meowkitty

meowkitty

11
3
Answered my own question by doing a quick search on it. Wow, that's bad! There is tons of stuff Arduino controls. I guess that's what happens when ideas happen faster than searches.

Still I'd like to hear your thoughts on the AC/ventilation strategy to see if this idea is even worth the effort...vs. just sealing the two rooms up and running a dual zone mini split (12K+9K), which I'd probably install anyway for summer.

Anyone have any thoughts on this?! Help me out!
 
fishwhistle

fishwhistle

4,686
263
Last edited:
meowkitty

meowkitty

11
3
Ah yes, great suggestion fishwhistle. I've perused his thread a couple of times now. Tons of good into. I'll hit him up to see what he thinks.

Indeed, I do have a tendency to over design/build many of projects. Sometimes it's good, and sometimes just creates more work with little benefit. Trying for efficiency here, but there may be room for a less automated approach on the passive/active ventilation. I suppose I could just keep an eye on the weather daily during the summer and run AC only on hot days (and during "day" time, of course.) The other three seasons could probably run on ventilation alone (again sealed, during "day" time.)
 
Top Bottom