Please take a look at my grow room diagram

This is an 8x12 shed. All dimensions on the diagram are estimates which include insulation (accurate within one inch) and the drawing is not to scale.




Things I'm "sure" of but don't have included on the drawing:


I want to vent the 4" inline fan (approximately 200 CFM)that will be pulling heat from my grow lights echausted underneath the shed through a hole in the floor.


I want the 8" inline fan (approximately 800 CFM) that is sucking air through the carbon filter to be exhausted into the "L" shaped section of the shed. There should also be an exhaust on the roof in that section of the shed (one of the ones that rotate).


All ducting will be insulated.


I want ONA buckets in every room.


There will be a shelf on the 3' 6" wall, in the room with the inline fans, for nutrients, soil and so on.


All fans and ballasts will be mounted on 1/2" rubber to reduce noise produced by vibration.


Panda film and PVC pipe will be utilized to prevent problems from spills on the grow area.




Things that I'm unsure about:


How many plants I should have in the grow area.


How I should space plants apart.


How many 600 watt HPS lights/fixtures I will need.


Most efficient lay out for the area to allow for both good yield and accessibility.








All help is appreciated. As a side note, there is a good chance that I will add a veg cabinet to the "L" room in the future.

clone veg and flowering setup. put the flowering in the top room and setup your cloning and mothering stations in the lower room.

Thank you for the input, that's the eventual plan. For now I just want to have the one large room. I will be taking the plants from seed to harvest there probably 3-4 times before I get set up for something like that.

There are several other things that I should have mentioned. This needs to be stealthy. It's okay that it won't look like a normal shed once you're inside, but plants being visible as soon as you open the doors to the shed is a no go. Also, the ceiling is not flat. The center of the ceiling is 8' tall and the lowest parts, up against the walls, are about 6'11.

Invest in light movers on light rails and exhaust your heat from the 8' tall part. This will increase your yields by up to 30% and also reduce the amount of lighting you will need keeping your grow room cooler. That actually works to your advantage if you are going to run an ac and use CO2. Also, if you want to be stealthy make sure u get quiet fans or insulate them and hang them on rubber bungie cords to reduce vibration. You can also never have enough fans for air circulation. That helps get thicker stalks so you don't have to support them as much later on and ensures that fresh air is moving through the canopy at all times. Look at my results. What i told you is what i do and my ceilings are only 6'11 too. Here is what i got going on.
https://www.rollitup.org/grow-journals/676886-day-42-flowering.html#post9253992

I was just going to lower the lights manually my first several goes at it. A proper light mover is definitely in order, though. My thought was to vent into the "L" section and then from there expel air through a vent (the ones that spin) from the top of the ceiling. I won't be doing CO2 initially. That *may* come later, but I'm hoping between the cooling from the AC and the circulation of air from the 8" fan and the fans inside the grow space that additional CO2 won't be needed.

Very nice grow btw.

Yea you gotta start somewhere. Thanks for the like. Here's the deal with CO2:

Air that is from the outdoors typically contains about 300 ppm of CO2. Photosynthesis in marijuana plants peaks at 1500 ppm. If you think about it like this say the amount of CO2 in the air is directly related to how fast your plants will grow due to the rate of photosynthesis being based on CO2 availability. The bigger and faster your plants grow the bigger your yields. What i am saying is that the amount of CO2 in your air is directly related to the amount you harvest. This increase is nearly 50% so adding light movers and C02 your looking at up to 80% increase possibly. Adding mylar is another 10% so you nearly to double what you would get normally. If you want message me and i can help you more.

It's my understanding that in order to make the most of increased CO2 levels you must also increase light output and nutrient input. The logic is that if CO2 helps move things along faster you need more of everything else to fuel the growth. I'm also under the impression that you're only supposed to run CO2 when your lights are on.

How is your room exhausted to keep the CO2 PPM up and heat down? Seeing as I'm growing in a shed, I don't have central air from the rest of the house to keep ambient tempatures down around the grow.

Koenreich said:

It's my understanding that in order to make the most of increased CO2 levels you must also increase light output and nutrient input. The logic is that if CO2 helps move things along faster you need more of everything else to fuel the growth. I'm also under the impression that you're only supposed to run CO2 when your lights are on.

How is your room exhausted to keep the CO2 PPM up and heat down? Seeing as I'm growing in a shed, I don't have central air from the rest of the house to keep ambient tempatures down around the grow.

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That is correct. Yes a good CO2 system can offer huge increases in yield but you need a dialed in space to get that boost. Typically the lights are air cooled and isolated from the room and the room is sealed and an air conditioner is used to cool the room.
You want to exhaust hot air up not down.
I'd run 2 600W lights in the top room.

MrEDuck said:

That is correct. Yes a good CO2 system can offer huge increases in yield but you need a dialed in space to get that boost. Typically the lights are air cooled and isolated from the room and the room is sealed and an air conditioner is used to cool the room.
You want to exhaust hot air up not down.
I'd run 2 600W lights in the top room.

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Thank you for your response.

I was planning on air cooling the lights and venting them out the floor (and into the ground, actually) because I didn't want people to be able tell that the shed is expelling a lot of heat when it's cold outside. I figured any losses by running hot air through insulated duct work would more than be made up by cooling the lights to begin with and also the AC unit.


Not being dialed in yet is what is keeping me from putting money into a CO2 system just yet. I would like to keep it as simple as possible until I have a better understanding of what I'm doing.


As for the lights, why two? I had the thought in my head to go with three 600 watt HPS lights because I thought the plants would make use of the light and maybe even make up for my novice errors. Any advice for light configuration, number of plants or grow pots?

Two 600s each covering about a 3.5'x3.5' footprint uses almost all of the width of that area and leaves you a 1' wide strip so you can move and get to plants. Trying to cover the entire room makes getting to plants at the back a pain in the ass. Two 600W lights will produce a lot of bud even if you get a crappy yield.

Awesome, thanks for the insight. How many plants would you suggest as a minimum and maximum for the space I have available?

This an outdoor shed? As in a garden shed? Be very careful. Police are not the only ones who use FLIR, rival growers also do looking for places to rob. That shed is going to glow like a bitch.

It's an 8x12 metal shed. I planned for the heat that will be generated with the design. The inside will be heavily insulated (after I finish wiring it up for electricity), the heat from the lights will be exhausted through the floor and into the ground. Also, the AC unit should keep tempatures in check in both the grow room and "L" shaped room that the grow room will exhaust into. As was stated before, that room will have a vent at the top and I'm confident that it shouldn't actually need to expel *that* much heat. In any case, I've planned for it as best as I can and hopefully any heat signatures that could potential be picked up will not look much different than what you could expect from a metal shed anyway.


Any additional suggestions are more than welcome.

If you're going from seed and can't keep mothers I wouldn't do more than 1 plant per sq ft, potentially as few as 6 with a long veg time. I would probably do 12 to shorten the amount of veg for the first cycle. I'd also make setting up a veg area a priority to keep clones of good plants as moms and because a perpetual setup lets you save a lot of veg space because you only need to have a few plants ready to flower at a time while vegging a whole batch requires use of more space when the plants are all about to be flipped at the same time.
If you can go 12/12 from rooted clones with 0 veg you can get away with up to 4 plants per sq ft.

Koenreich said:

It's an 8x12 metal shed. I planned for the heat that will be generated with the design. The inside will be heavily insulated (after I finish wiring it up for electricity), the heat from the lights will be exhausted through the floor and into the ground. Also, the AC unit should keep tempatures in check in both the grow room and "L" shaped room that the grow room will exhaust into. As was stated before, that room will have a vent at the top and I'm confident that it shouldn't actually need to expel *that* much heat. In any case, I've planned for it as best as I can and hopefully any heat signatures that could potential be picked up will not look much different than what you could expect from a metal shed anyway.


Any additional suggestions are more than welcome.

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That is the problem, there should be no heat signatures from a metal shed at all. Because it is metal, and conducts heat much easier than any other material a shed could be made from, you would expect it to be the coldest thing in the garden. ANY heat signature from it would arouse suspicion. If you can vent into the ground, i would vent everything into the ground, and leave nothing to chance. Also AC requires an exhaust, so it is the exact same thing exhausting that as you would exhaust an inline fan, if not more heat generated by the AC itself. Be careful man. I would start looking at possible lines of sight from public access points to your shed. If you can see it from the street, i would scrap the idea. Every safety guide to growing dictates you do not grow in a shed.

Also if you are in the US a search warrant is not required for sheds and garages not attached to the house.

Ya, i was going to say that you cant have the a/c hot air going into your flower room. And as for stealth. Those inlines make quite a racket if yu dont have silencers on them.

The shed is my only option for growing.


You can not see the shed from the street in any direction. The AC will get fresh air from the passive intakes in the utility room, just like the inline fans. I'm hoping that air will be moved through that small room at such a fast rate that the temps stay pretty close to the outside temps when we're not in the winter months. It may have been hard to see, but on the diagram I indicated that there would be duct silencers and insulated ducting on both inline fans. Also, I'm going overkill on the fans so i can wire in speed controllers and run them at 50%. It's possible that I will build an enclosure for each fan if noise is still a problem. If anything vibrates it will either be hung with bungee cord or mounted with 1/2" rubber. Between all that and a thick layer of insulation, noise shouldn't be too much of a problem.

Hot air will not be pumped into the grow room. The heat from the lights will be sucked out by either a 4" or 6" fan. The 8" fan will do it's job pulling air through the carbon filter and I had planned on exhausting that into the "L" room and adding a vent to the ceiling. If you all think it would be better to push that air out the floor it can be done but I was under the impression that the cool air being vented into the "L" room from the grow room wouldn't be hot at all and could actually help keep temps in the shed down. Any hot air at the top of the room would be exhausted through one of those spinning vents. Speaking of the AC, it'll get it's fresh air from the passive intakes, just like the inline fans. Cold air will be blown into the grow room and a drip line will be attached to the AC to take care of condensation.


It's worth mentioning that I intend to rent a FLIR camera once the build is done so I can be sure that it is in fact stealthy.




Again, I appreciate all the input from everyone.