Noob's guide to growroom set-up : a work in progress

Ms Stinky has shamed me. :(

Back when she first hung the â??complete noobs guide to growingâ?�, we talked about doing a â?? noob's guide to grow-room set-upâ?�. I never got around to it- then I saw her â?? garden type examples threadâ?�, and it guilted me into getting my ass in gear.

So here we have ( at ) it- the â?? Komplete Noob's guide to setting up your first growroom.â?�
I'm gonna start with some meta stuff- questions to ask yourself before you even start. After that, ( I think) I'll try to cover reflective materials, ventilation setup/ odor control, hanging and alignment of lights, and whatever else comes up as we go. We'll see.:wtf:

Let's start with the ultimate meta-question-

What is your goal for this project?
(I'm specifically not going to talk about grows of over 1200 watts in a single space- I think that's a reasonable cut-off between personal use and small-commercial gardens. Most folks who are burning more than two 600's in flower are producing enough over headstash to be .be producing a small income stream, and the crazed Maoist in me wants to let them figure it out for themselves. For folks who are leaning that way- be advised that ventilation, in particular, does not always scale up linearly.)

Are you hoping to grow to cover your own smoking? How much do you smoke a month? (Keep in mind that you are automatically supplying everybody else in your household that smokes.) How much does your household smoke in a month?

If it's just you and maybe a spouse/partner, and you only smoke a few times a week, you could get away with a 250w hps, in a 2x2 or 2x3 foot space. I know that people work in smaller spaces, but it's never struck me as a good place to start- and most of the folks I've known who were under CFLs wished that they had the HPS 250. T-5 florescents are another good choice- esp. if there are ventilation issues.

Daily smoker? Husband/wife/roommate of a daily smoker? You'll want at least a 400w HPS for flower, and a 600 if you share a lot.

Multi-Smokestack household? A 600HPS will probabley keep up, but three Marley-types will want to go to 1 k. If you see yourself scaling up to small commercial, go for the 600- they scale up nicer, IMHO.


How serious do you think you're going to get? Are you the kind of person who gets caught up in hobbies, or do you pick things up and put them down as the mood strikes? If you are- move up one light size. (ie, from 250 to 400, or from 1K to two 600's). Have a look at Rock.Steady's guide to see what I mean. (:D)

What's your budget? ( Throughout this I'm going to point toward what I feel is best practical practise, though I'll try to sketch out both minimal and best possible as I go along. I'm sure a LOT of folks are going to disagree with me about best practical approach- feel free to comment. Do me a favor, though- quote the part that you're disagreeing with, so we don't have to be scrolling up and down as much in the inevitable pie-fights.)

Anyway, if you're thinking about setting up, you should have a space in mind. Picking a space is a very important decision- I'd plan it out through harvest and drying before I so much as cracked a seed.

Really, the ideal space for a personal grow is a 4x4 to6x8 basement closet with a solid, lockable door and a window, with an exterior wall that's far away from any trafficked areas. Life, unfortuneatly, is rarely ideal. There are quite a few factors that make for a good growing space- so as you think about a spot, I'm going to ask you to answer a few questions, we'll assign scores to different answers, and try to come up with a formula for choosing a â??roomâ?� to grow in.

The best way that I can think of to do this is a 1-5 scale, with 1 being the low or minimal end, and 5 being the best you can think of. We'll end up assigning each question a multiplier value so that we can rate the relative importance of each factor. In example, the conveniance of not having to carry water too far is important, but NOWHERE NEAR as important as discretion/security. I'd much rather carry water than handcuffs. I'm also going to define some of the questions as we go.

A.) Is the space the right size?( 1-5)
I'd say the minimum size for a 250 is 2x2, for a 400 3x4, for a 600 4x4, and for a K 5x5.
I'd also say that the maximums are 3x3, 4x5, 6x6, and 8x8 repectively. 4-6X8 is a nice configuration for two 600's. (I'm sure that we'll get a bunch of opinions about this.) If it's too big, will you be able to cut it up?

B.) Will you be able to provide enough fresh air? (1-5)
How accessible is ventilation? Is there a window? Attic hatch? If you're thinking small box, will one side be against a wall, allowing you to cut ventilation holes?

C.) Is the space private? (1-5)
Is there any reason for anybody else to need to access the space with no or little notification? Do you rent? Do you have tenants? Are there circuit breakers or plumbing shutoffs in the space? Water heaters? Does the space have a â??wet wallâ?�?

D.) Is the space discreet? (1-5)
Is it close to your front door? Have windows facing the street? Would the mailman/ oil delivery guy/ pizza guy ever notice anything?

E.) Is there adequate power? (1-5)
Will you be able to run your choice of lamp, plus another 50% to cover fans, pumps,etc?
You can't run more than a K safely on a 15 amp circuit- Well, yeah, two 600's, but you won't have room for as much as a clock-radio by the time you're done.

F.)How far do you have to carry water?
( in-room water would be a 5, up two flights of stairs a 1)

G.) Is the space stable in terms of temperature? (1-5)
Are you going to bake in the summer, or freeze in the winter? Attic temps bounce around a lot, from way-too-hot to freakin freezing, depending on insulation. Basements tend to run nice and cool year-round. Living spaces are usually in the 65-75 range, and are OK- but I don't run central air, so my second floor bedrooms would probabley be too hot in the summer. Yours might or might not.

H.) Is the space available? (1-5)
Are you thinking about taking over the space where your wife keeps her knitting? Her ski's? Her chainsaw? Is this where your roommate keeps his comic book collection? Action figures? ( Growing in a group house is an exercise in politics that would make Kissinger sweat)

Now let's talk multipliers...

I'm going to assign some â?? importanceâ?� multipliers, and I'll try to explain my reasoning. Feel free to offer your opinions/solutions- but again, please quote the passage that your critiquing, so my scrolling finger doesn't cramp.


A) appropriate size- On a 1-10 scale of importance, I'd say this is a 7- not critical, but important. It's important that you can make it size well- a 4x4 area of an 8x10 bedroom will work great for a 400, if you can partition it off so that you're not wasting light.
So a perfect size (5)would get you 35 points (5x7)

B.) ventilation- I'm going to say another 7. You can get around vent issues by upsizing fans, building lung rooms, etc- but thinking thru your ventilation is key! Great access would give you a 5, so you'd get 35 points ( 5x7).

C.) privacy- big ol' 10. (Do I have to explain why?)

D.)discretion- not as important as privacy- you can hide things in plain sight. Still, if I have a vent sticking thru the wall, I don't want it to be right by the front door. Let's call it an 8.

E.) Adequate power- HID lights suck a good bit of juice, and overloaded wiring can cause fires- which will get you clipped at best, or kill someone at worst. However, inadequate wiring isn't that bad to remedy. Try to avoid extension cords, and if you have to use them- buy, brand new, the heaviest extension you can find, in the correct length for your application. Extensions are expensive, but much less so then lawyers. ( No cords on the floor!). As this is fairly manageable, I'm going to give it a 5.

F.) Distance to water- is really a conveniance thing. Lugging H20's a drag, but not a deal- breaker. Call it a 3.

G.) Temp Stability- can make or break a grow. Again, it can be managed, but can be a real PITA- and even worse to try to retrofit a running room. Let's call it a 6.

H.) Availability- you really don't want to step on anybody's toes. No matter what, the grow will eventually cause friction with anybody else who lives in the space. On the other hand, if nobody's an asshole, you should be able to make it work- but if push comes to shove, you'll get shoved. Try not to push. Let's give it a 4.

Ok, so take your â??scoreâ?� for each question and multiply by the appropriate â?? importanceâ?� factor to get the weighted value of your answer. Then sum up the weighted values to get your spaces grade as a potential grow space.

The perfect space would score a 250. The worst space on earth would score a 50.

I'd give a score of 210 to 250 an â??Aâ?�
170 to 209 a â??Bâ?�
130 to 169 a â??Câ?�.

I would'nt even think about working in a space that didn't score at least a â??Câ?�- that's just asking for trouble. Y'all can if ya want to, but don't say that nobody warned you...


Room Prep- First things first. Go in there and shut the door. Turn any lights off. Wait five minutes... Can you see anything? At all? Any light anywhere?

If you're going to line the room in Panda, it'll take care of a lot of light leaks. If you're using mylar or white paint, you're going to want to fix the light leaks before you paint/hang- mylar in particular will let a lot of light thru.

Pros&Cons

Mylar Pros highly reflective
easy to hang

does not wear well
Cons makes noise in fans
electrically conductive



Panda Pros very reflective
10' wide
durable and cheap

Cons may be hard to source
10'wide
hard to hang alone




White Paint Pro cheap
easy to apply
easy to repaint

cannot clean
Con messy to apply
must dry before plants go in

An easy way to light proof a door is to hang a length of panda over the door opening, with a self-adhesive zipper to close it up. Windows can be covered w/ panda or luan- I usually hang a mini-blind between the glass and the covering as camoflage. If you're going to vent thru this window, remember to leave it open a few inches before you cover it!



OT- this is all I'm good for tonight. I'm going to hang a couple of placeholder replies under this, so that I can edit in further narrative in a linear fashion.

I'd love to get people's feedback on this project.

Very good post. i like the points rating questionaire.

This is going to be one of the best threads that canncom has ever seen, PERIOD.
If I may be so bold as the write the blurb on the back of the book, lol, Rhizome comes equipped with a background in horticulture and many years' experience applying it to commercial-scale hydroponic food crop production.
Sticky for you!!! :D
Rhizome, your edit window is only a few minutes so anything you need moved around may be a tough one- even mods can't change the order of posts.
I've been doing mine by writing it up in a word processing program and then pasting it.
Thanks for this effort!!!

If I may add a few things here.....they are probably pointless thoughts but I can't help but throw them in. With the few people I've worked with these things seem to be what people have 1. the most trouble understanding. 2. Not realizing the importance of such things as ventilation, temp control, humidity etc.....until they have the problem which, interestingly, they wouldn't have if they had realized it was VERY important at the beginning. Lighting, room temps and good ventilation are the big three imo.

I see this thread as being for those who REALLY want to approach growing right but oddly, lots of people don't seem to want to....they want the easiest, cheapest way to go....until they find it doesn't produce the same results as the RIGHT way to do it and then there's all sorts of fussing, complaining and moaning about the price, the time and the energy.

So....new growers....pay VERY careful attention to this thread.....it is EXCELLENT. And when Rhizome (quietly) says something important (example.....room temps can make or break your grow ) USE that information or then he'll have to have a thread titled "How to Make the Typical Cheap, Easy Noob Growroom Into Something That Will Actually Grow Plants."

Great work Rhiz..... you're such a sly devil. :) :thumbsup:

As always rhizome delivers in pure analytical fashion.
You sure your not a vulcan?

My favorite is the verbage used.

Quote:

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Originally Posted by rhizome

three marley types will want a 1k.

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So far my favorite.

The quiz is a excellent way to categorize spaces, budgets, and of course the key questions of what, how much , and where. Since its still early on this I am assuming there is lots more to come. Seems that might thread should maybe be in Basic Growing Growroom Setup

/subscribe

OK- let's talk ventilation. The most important points here, IMHO-

-Nature abhors a vacuum- even a relative one ( or... pressures will tend to equalize)
-You're not moving air in, and you're not moving air out. You're moving air THROUGH.
-Questionable odors are probabley the #2 or #3 reason that folks get caught- ( Talking out of school would be #1).

The ventilation system is one of the most critical aspects of growroom design. I'm going to shy away from discussion of AC use for now- most personal gardens can get by without, and those that can't will generally be served by the climate control system of the dwelling. For now, we'll assume that that primary cooling/ dehumidification is going to be through exhaust.

The ventilation system, at it's simplest, consists of three elements- the intake, the exhaust, and the blower/fan. Choices here are about equivalently important. Let's start with fan sizing, which is tied to room size (in cubic feet) and choice of lamp.

For now, I'm going to assume that people are using a single main exhaust blower and a passive ( unpowered) intake. (Active intakes can be very effective, but great care must be taken to insure that intake CFM does not exceed exhaust CFM. In this case, you'll achieve a positive pressure condition in the growroom. This excess pressure WILL disperse in an uncontrollable manner, bringing with it delectable but dangerous aromas.( See above primary principles.) I would advise always trying to run at as close to nominal pressure as possible, with any variation from nominal being negative.)

Calculating cubic footage is simple- length x width x height = cubic volume. You want a main exhaust fan which can exchange the air in your room in no more than five minutes. I try to budget for three minutes. Let's comprimise at four minutes. Therefore, a 5x5 room with 8' ceilings would require a fan capable of [ 5(l) x 5(w) x 8(h)] = 200 cf. 200 cf / 4 (minutes)= 50 CFM for your fan. Doesn't sound like much, huh?

Now let's get into efficiency factor multipliers. ( This is where it all goes to hell).



Take your unloaded CFM requirement, and add 10 % for each foot of flexible ductwork that you are exhausting thru.( ie- you need to clear a 4x4x6 room thru 10' of ductwork. That's {96 CF /4 (minutes)}= 24 CFM + {(10'x10%)=100%} 24 CFM+100% (of 24 CFM)= 48 CFM. ( Exhaust loaded CFM)

Now take your (E.L.)CFM and multiply it by 1.5 for each 90 degree bend in your exhaust ductwork, cumulitively. ( Ie- you have a loaded CFM of 48 cfm that makes two 90' bends in it's ten foot length. That would be (48 x 1.5)x1.5- or 108 cfm loaded w/ bend factor.)

OK- CFM requirements are adding up pretty quick, and we haven't even talked about odor control. I personally think that carbon filters are the best method of odor control- but I figure that we'll get a healthy debate about this too. I like to put my carbon filter inside the room, near the ceiling. I like to set up the filter before the fan, so that air is sucked from the space, through the filter, through the fan, and then out of the space. This way, all air being pressurized by the fan has already been de-odorized. You can blow through the filter if you mount it after the fan, but be aware that between the fan and the filter there will be a zone of pressurized, stinky air- any leaks in your ductwork moving air from fan to filter will create potential smell issues. ( See primary principles above.)

Take your EL CFM ( including bend factor) and multiply by 1.3 to allow for intake restriction of the carbon filter. Don't forget to allow for ductwork between filter and fan!

So, if we're running a filter that's 3' away from the fan- our total duct length ( in the above example) is now 13'. Let's adjust our math.

We have a 4x4x6 room. Our total duct length is 13'. We're using a filter. Our math now looks like-

4x4x6 room= 96 CF. Divided by 4 minutes is 24 CFM required.
24 CFM + 130% ( 10%x13')= 55.2 CFM ( I'm gonna round to whole CFM, to try to minimize decimal over-runs)

(55CFMx1.5)x1.5= 124 CFM â?? to allow for our two 90 degree bends.

124 CFMx1.3 ( to allow for air velocity lost to the filter) = 161 CFM.

So we're looking at a 161 CFM fan.

But wait- we haven't even thought about how our light's going to effect this. We could go off into a discussion of determining system effeciency by measuring intake and exhaust temperatures so that we could calc differential temperatures, but I don't know how to make the little â?? deltaâ?� symbol on my laptop keyboard, so I'm gonna skip that and assign yet another load factor...

For a 250HPS- multiply by .75
For a 400- multiply by 1
For a 600, multiply by 1.3
For a K, multiply by 1.6.

(Let's be reasonable here- I know that my math falls apart if you're running a K in a 4x4x6 space â?? but is it reasonable to run a K in that space at all? In your very first room?)

So to put a 600 in that room, we'll take our base adjusted CFM and multiply by 1.3 .
161 CFM x 1.3 (lamp factor)= 209 CFM fan/blower to power the ventilation system.

I'm not going to blow out the math to establish what room intake sizes should be to prevent drag on the system- that get's WAY crazy... Instead, I'm going to propose that we use a rule of thumb stating that â?? Intake area should be fan CFM x .5 square inchesâ?�

Applying this rule, our 209 CFM fan would require an intake area of about 100 sq. inches- or 10â?� x10â?�. This does'nt have to be monolithic- two 50 sqâ?� intakes will work as well as one 100 sq â?? intake. You can check your intake sizing by just cracking open the door to the room and firing the fan- if the door moves at all, you need more intake.

When shopping for fans, round up- if you need a 209, and your choices are 180 or 240, grab the 240.

OK- gonna break here again and see where folks have pointed out my mistakes.

Quote:

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Originally Posted by GoldenGoblin

As always rhizome delivers in pure analytical fashion.
You sure your not a vulcan?

---

I could totally buy this myself Goblin. :D :thumbsup:

Vulcan? No.

Irish Catholic. ( We know how to wait.)

Well I won't go hunting with you anyway because of your avatar.
:D

very good on the Chapter the Second- Sizing your exhaust and intakes section
very informative

OK- back to it...

Couple more ventilation notes, and then on to room prep.

I heartily recommend using thru-wall flanges anywhere that you need to run ductwork thru a partition. Fer instance- You're using a window to exhaust... First, Mount a mini-blind in the window.(Camoflage from outside). Leave the window cracked open a few iches top and bottom,so that air can flow easily around the sash. Now cut a piece of luan (good) or cardboard (cheap) that fits inside the interior casing, flush against the stop. ( The stop is the piece of molding that holds the sash in the window opening, preventing it from falling into the room.) This should block the entire window. If you're dealing with a newer (vinyl) window, you won't have a stop- instead, the body of the window unit will but right up against the casing. You'll mount your blackout panel against this instead.

Put the blackout panel in place and make sure it fits well. Determine where on the panel you're going to run your exhaust- cut a hole ( holesaw), sized to match your fan's output dimension. Home Depot and the like, in the HVAC section, will have â??starter flangesâ?�- they're used to mount branch ductwork off of sheet metal mains. They look like a little top-hat that somebody has punched through. (Again, sized to your fan's output dimension- if you're using a 6â?� fan, you'l be using 6â?� flanges and 6â?� duct) Mount this with a couple of short screws over the hole in your blackout panel, so you have a nice clean, light-tight place to mount your ductwork. This will essentially eliminate issues with ductwork coming loose ( and beaming a veritable bat-signal out your window), which is not uncommon when you start pressurizing flexiduct. If you wish to use this window as an intake as well, put your exhaust port high, and use multiple intake ports at the bottom. To light proof the intakes, merely attach ductwork to the starter flanges that you put over your intake holes and allow to bend down 90 degrees. I'd also advise ( strongly) putting insect screening over the intake holes from the outside- you can just glue it in place with caulking.

On a wooden window, I'll usually affix this with some wire nails ( very wee)- On a vinyl window, I use cheap acrylic non-siliconized caulking, as this can be cleaned off pretty easily if and when you need to make the room go away. Don't use the siliconized here, as it'll be tough to clean up perfectly.

If you're ducting thru walls or ceilings, you can usually use â?? duct couplerâ?� units- tube of sheetmetal, sized to fit inside your ductwork, that are designed to join two lengths of duct. Cut your holes ( with the appropriate hole-saw) and slip the coupler in place. If your walls are too thick for the coupler unit to go all the way through, you'll need to use â??hard ductâ?�- the sheetmetal stuff. Also home depot. Measure the length you need to have and cut to fit. Most easily cut if you open it up, lay it flat, trace your measurement several times with a utility knife, and then bend the sheet metal back and forth until it pops apart. Beware of razor sharp edges!

OK- so we know what our ventilation looks like, we have all of our flanges mounted- couple more details before we treat the walls.

Find your ceiling studs- a studfinder will cost about $15 , also at Casa de Pot, and will be good for really unlimited humor value ( Fer instance, you can walk up to your hubby/BF, wave the stud finder, (which doesn't go off), and mumble â??...hmm...guess I'm still looking..."- My daughter has been known to bring one to bars...) If you have a studfinder, you can skip the next paragraph..

You can often find studs by tapping on the surface and listening to the sound it produces- an open wall cavity will sound boomy, while tapping over the stud will produce a deader sound. This will get you within a few inches- now you need to poke thru the wall surface and look for wood. If you have plaster and lathe ceilings, make sure you are hitting frame and not lathe- if you hang a heavy light fixture by the lathe, you'll probabley be allright- but maybe 1 time in 10, the lathe will eventually pull free, dropping your light and 50-100 lbs of ceiling onto your garden. (Same thing with drywall anchors) Establish the pattern of your ceiling studs ( really joists, but whatever) and trace till they meet the walls. Mark the wall where the stud hits, extending the mark down maybe 3-4 â??s. Hang your panda/mylar/paint on the ceiling. Now, before you cover the marks on the walls, snap a line from mark to mark corresponding with the joist run. These show you where you can hang things from the ceiling, SAFELY.

So go buy a studfinder- or borrow your dad's ( He'll be so proud).

OK- you're ready to paint, or to hang your reflective film.

Mylar comes in 48 and 54 inch widths, and 1 and 2 mil thicknesses. I really recommend using the 2 mil if your going to use mylar- 1 mil tears like tissue paper. If using mylar, be aware that it's not perfectly opaque- you need to black out any windows that you haven't already.
Start in one corner on the ceiling. Unroll about 6â?� from the roll and tuck into the corner where the ceiling meets the wall, and put a few staples in. Now unroll across the ceiling, keeping the edge of the mylar paralell and butted against the paralell wall. Put staples in to tack it up every couple of feet. Keep things tight and neat- Neatness counts a whole lot. Roll right over any ventilation flanges you have previously mounted. Repeat until the ceiling is covered. Rooms are never perfectly square- overlap your mylar by a few inches so that you can adjust.

Once it's all up, tack it in place thoroughly. Staples will pull thru mylar very easily- anywhere that you need to staple, put a little square of duct tape up first and staple through that, to re-inforce the mylar. (Duct tape, by the way, uses an adhesive that gets soft when warm- don't rely on it as a growroom fastener. Here, it's just a buttress) Use a Sharply to translate your joist marks up onto the ceiling covering.

If you're hanging mylar alone, it's usually easier to run the wall covering in vertical strips, as gravity will help keep it straight. If you have a partner, run it horizontally ( One holds in place while the other staples.) Again, roll right over blacked out windows, vent flanges.
( Don't cover the door.)

Cut out the mylar to expose any electrical outlets, vent flanges, etc. I like to poke a hole in the center of flanges and make asterisk (*) shaped cuts out to the edge- gives ya a nice clean fit. Of course, be careful using a knife around an electrical outlet. Mylar is electrically conductive, so avoid the temptation to tuck the mylar under the cover plate, no matter how much better it looks.

Panda's similar, but 10' wide off the roll. You'll want to measure the length of your walls, and cut panda a few inches longer. Panda's folded do that you can pull one edge out- align w/ ceiling edge, letting a few inches run down onto the wall. Staple heartily. Now unfold panda across ceiling, stapling as you go. Panda's a lot tougher than mylar, you won't need as many staples. Same deal, same cautions regarding vent flanges, electrical outlets.

Paint's pretty straight forward- just don't lose your joist marks! Caulk the edges of any flanges going through a window blackout, to ensure that you won't have tell-tale glow from outside.

Might as well mylar, paint, or panda the inside of the door while you have all this stuff out. Make sure that the door will close properly! If you have a louvered door, or a door that really doesn't fit well, hang panda over the inside casing and install a self-adhesive zipper to allow you to open and close it. Wherever you got the panda will have the zippers, or you can get them for tarps at a lot of lumberyards. You're looking for a â?? tarp zipperâ?�.

OK- so now you should have a highly reflective room. Grab a grease pencil or sharpy. Go inside and close the door. Block off your duct flanges. Turn off your worklights and hang out for at least 5 minutes to allow your eye to adjust. The ONLY light leaks that you should see should be incompletely blocked ventilation flanges. Anything else- circle it in greasepencil or sharpy, so that you will be able to find it again with the lights back on. Doors can be a drag- do the panda&zipper thing, or use v-seal weatherstripping if you have a problem. A door sweep is also a really good idea- go look at your storm doors to see what I mean.

This is very important- it's much easier to fix stuff now, while the room is empty.!

Once you have plants in there, you will not see the room in the dark- most folks discover their light leaks when they start seeing hermies. Prior Planning Prevents Piss Poor Performance!

Ok- gonna break again. In our next installment, you'll see why it's so important to know where your studs are.

Prep work's a drag, huh? Don't worry, it's all very worthwhile.

Shoulda mentioned last installment that you should snap or otherwise draw a line showing where your ceiling joists are. You can do it now,though.

So why do you need to know where your studs are?

I'm gonna actually refer you to another old fart . ( Go ahead, click the link)

You're going to hang an HID lamp from the ceiling. There are three ways that a fire can start in a growroom. One of them is to overload a circuit or powerstrip. Another is a flammable material too close to the lamp. The third is for your lamp to have fallen.

Go check out the first page of the â?? Plant Problemsâ?� forum. There's a new thread on there every single day where somebodies dropped their light onto their plants- and that's really a best case scenario. Worst case is that your light falls and ruptures the bulb, IGNITING A FIRE!! Somewhere in the middle is your light falling while you are working under it, causing painful burns. ( Painful, painful burns...)

Remember, the only constant in life is entropy- shit falls apart...

I don't regard an HID lamp as any more dangerous than a microwave oven. (That being said, I have rarely suspended my microwave over my head.)

The reason that you need to know where your studs are is that you are going to hang your HID lamp, from these joists.
Would you hang a microwave oven from string tied to a little wire hook in your ceiling drywall? If you would, would you take a bath underneath it?

Me, I'd use chain, hooks rated at least three times the load that I was going to hang on them, and I'd have those hooks very firmly mounted onto ceiling joists. But if I hung it, then yeah, I'd take a bath under it.

I'm sure that this sounds like hyperbole, and it sort of is- but the point is safety, so I don't feel bad about it.

By now, you should have a very specific plan of how your going to lay out your plants- if you don't, set up your containers, trays, what have you , and do a layout plan- figure out how you're going to water things, where things should go so that you can reach them easily- Frequently, it doesn't make sense to hang the light in the center of the room. It's a whole lot easier to re-arrange empty pots until you have something that works for you, than it is to move pots around to water. Make sure that there's room for you in there too, and that you'll be able to reach the pots with a full, heavy container of water- or if you're going to do hydro, that you'll be able to maneuver five gallon buckets of water in there, get nute samples easily, that kinda thing.

Anyway, do your layout, and get a look at where your plants are going to end up when they finish flowering. This is going to determine where you end up putting your light. Assuming that your walls are fairly level, you can take measurements on the floor and transcribe them to the ceiling- Just make marks on the floor and use a plumb bob. ( Borrow your grand-dads- it'll thrill him)

A quick tip- the great majority of the light from an HID lamp is emitted from the sides of the arc tube. I always try to align the arc tube so that it's parallel to the shorter walls of the room- this gives you the most efficient distribution pattern.

Personally, I like to have the light suspended from more than one joist, although I suppose that if you actually have a complete failure of a joist, the lamp will be the least of your problems.( I used to do swing stage work in an urban area- I'm really into redundant back-ups.) If I'm at ninety degrees to the joists, then a couple of hooks and we're done- if I'm parallel, I usually strap a plate across two joists and sink the hook in that. This also adds a lot of flexibility in placing the light, as I'm not stuck with the joist layout- if I want to be six inches further over, I have the option.

Hooks and chains are load rated. Always at least triple the load rating- ie a 20# reflector requires hooks and chains load rated at at least sixty #s. It's the cheapest insurance you'll ever buy, and the most likely to pay off. ( Speaking of which, if your homeowners underwriter ever finds out about you're doing this, they will never pay any claims for any damage- Are you going to walk into a courtroom and sue your insurer because they wouldn't pay for fire damage caused by your garden? Me neither.)

It's a really good idea to pick one hook on any given chain that you're going to use for adjustments, and crimp the others or otherwise ensure that they cannot possibly dislodge. Play out scenarios like:

You have walked into the room and tripped, falling directly onto the reflector.
Will your body weight pushing it to one side knock it off a hook?

You have been crouched over under the lamp, and misjudged it's location. When you straighten up, the back of your head touched the bulb- causing instant, searing (literally) pain. You thrash about.
Can you knock any of the hooks out by taking weight off of them or shaking them back and forth?

These things happen, and suck.

But they suck even more if they end up dropping your lamp onto your plants, onto your head, or into some water.

Ok, are you happy with where your reflectors hung, how it's hung, what it's hung with? Great- take it down. We need to strap more stuff on the ceiling- we did the light first because it's big, and position sensitive.

I usually do the carbon filter on the ceiling as well, hung from hook and chain. It's not as critical to have the filter perfectly positioned- Nice to have it nearish the light, as that's where airs often hottest, and center of spaceish- but pretty much anywhere reasonable on the ceiling's gonna do. As the filter will neither burn me or start a fire, I usually just hang it off one of the joists- sink two hooks, put chain on them, hold the filter up, wrap chains around filter and back onto same hook. Good idea to check the fit with the reflector back in place- also to make sure that it's really as easy to move the reflector around as you expected. Try to point the flange end of the filter toward the exhaust flange you installed earlier, or at least not away from it. The fan goes anywhere that's good between the two- again, heavy, joist. The fan will seem quieter from outside the room, where it matters, if there's flex ducting between it and the exhaust flange, and if you suspend it from a piece of chain or bungee, so it's vibration is not transmitted to the joist.

Now lay out your ducting, cut it to a good fit (Not so short that it wants to pull off the flanges, not so long that it's all over the place) For this, I use drywall hooks and cable ties- it doesn't weigh anything.

Ok, so we have your ventilation in place, with the cord from the fan just hanging down. Go ahead and hang the reflector back up, (no bulb just yet, and with the lamp cord unplugged from the ballast, if you can,) stand back, and admire your work. It's starting to look like a growroom in there.:thumbsup:

Let's break again here, and pick up with cable routing, environmental controllers, timers, and keeping the ballast off of the floor and therefore out of the water.

Bump in hopes of getting to read the rest of this great tutorial! Lots of interesting and useful knowledge to set your area up RIGHT!
Thanks, and lotsa K to ya!

Good work:thumbsup:

No comment from here....

Its all great. Just waiting for next installment:D

Awsome thread, Ive had quite a few set ups and have been succesful over the years but with these new tips I will definately be able to refine my space for the winter. Better yet an entirly new space, awsome! Feed my head some more man it's starving:thumbsup:
Hey stinky, I'll bet your keeping tabs on this one. This dude got some knowlege here. If geographics allowed you guy's could blow Amstradam out of the water with your combine skills. :jointsmile:

Great post, very informative, and alot of information that needs to be told... now if people will only read stickies, and search.
did i miss the part about electrical??? because i know you got some info on that!?

i have a wonderful solution to growroom wiring, but it is semi-advance

:thumbsup: another good one rhi

no comments, written wonderfully and easy to follow, hoping for more to come, but just one question.
im confused about the fans mentioned in rhizomes second part of the post, the passive vs active intake fans. whats the dif? and which is better? how much are they? do they make various sizes?
also just a few questions about exhaust fans- are inline the best, what about squirell cage fans? anyone have any suggestions on where to purchase these aside from online? and if online anywhere really cheap? hope someone can help me out!!!! sorry for so many questions
happy smokin
:jointsmile::rasta:

From what I know, He is referring to a passive intake as not having any fan at all, while an active intake is one that has a fan that blows air into the area.

As for exhaust fans, many people seem to recommend the vortex blower fans, mainly because they are cost-effective to run and that you can use a variable speed control with them. The dayton blowers are good at exhausting air too, but at a much higher electrical consumption. (compare a 6" vortex blowing at 449 cfm's and running 80 watts, vs. a dayton 465 cfm blower that consumes 2.9 amps (120v x 2.9A=), or 348 watts.

This place has decent prices on the vortex:
Vortex 6 inch Inline Fan 449 CFM @ Businesslights.com
HTH

Exactly- a passive intake doesn't use a fan.

Active intakes can add a whole new level of complexity and problems. You have to match airflow pretty carefully between active intake and active exhaust- More intake than exhaust will stink the place up, and an underperforming intake will limit exhaust cfm.

A passive intake ( that's large enough) will balance according to negative pressure created by exhaust.

I like can inlines for the bulletproof factor, and low operational noise. Also, they pre-package fan&filter for a couple bucks less than a la carte- so you know that they'll match.

One thing to keep in mind when comparing fans is static pressure capacity, if you need it for long runs. The inlines move a bunch of air assuming a low static pressure, but capacity drops pretty quick when air pressure on the exhaust side exceeds intake pressure- you know, like when you're blowing into a tube.

Squirrel cage designs maintain much better airflow against pressure, but chew a bunch o' watts doing it.

Different designs for different purposes.

I too like canfan inlines. They had an exhibit at a trade show that showed one of thier fans outsucked/outblew two of the competition for the same supposed cfm rating.

Great thread, very well written and informative. My 2 cents on the inline fans: The 6" Vortex is a monster for its size, not to mention a 10-year warranty if I am not mistaken. That's a big part of what sold me - that and its built really solid and dials up and down well on a rheostat type switch.

Can't wait to see the next installment!

Great thread! I'm learning a lot. Now you need to do one on cabinet growing. :)

Quote:

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Originally Posted by Mac420

well to start off im new at growing. my friend got me into it and now im starting to find it interesting. could you maybe recomend some sites and books that i could start reading up on the learn more about everything.:rasta:

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What is your situation? Are you growing in a cabinet or a closet? Are you planning to have an extra bedroom that gives you more room? Dirt or hydroponics?

A couple of books that I recommend in this order (look on Amazon for them):
1. The Indoor Marijuana Horticulture Guide by Jorge Cervantes
2. The Cannabis Grow Bible by Greg Green

Read the forums here and grow logs. Read, read, read. Ask questions once you have studied a bit. You can check out people's profile and sometimes reach them thru IM or myspace.com.

Good luck!

Will there be an update anytime soon? Very useful information here. Can't wait to see it complete.

great information here, thanks.

rhizome,
How about an update for us...I am really getting into this thread...

Thanks,
Peace,
Treetops:thumbsup:

What do folks want to talk about?

I was expecting a sorta conversational thing- sorta lost interest cuz I felt likr I was typing to myself...:(

Let's break again here, and pick up with cable routing, environmental controllers, timers, and keeping the ballast off of the floor and therefore out of the water.
[/QUOTE]

I was just interested in what was going to be the next update.....All your knowledge is waiting to be heard:thumbsup:

Thanks,
Peace,
Treetops :D

You've left so little out that there's not much to discuss really...
Lol ballast out of the water... Let me say on the record he's not kidding. You WILL spill something. It's not a matter of IF, it's a matter of WHEN.

I want to talk about environmental controllers. That's my next big leap into automation! Here's why. SO many of the problems I see new and even old growers having stem from inappropriate heat/cold cycles- even bugs breed faster when your temps aren't under control! My own experience with growing sad yellow plants in a high-temp growroom, even though I knew my shit backwards and forwards, really sucked. Looking back, dropping a k on a controller ($200) and set of accessories to plug into it (a/c ($150), heat ($30), co2 ($300), ducting ($25), fan($250)) would have been a good investment. :(
Shoulda listened to the guy at the shop...

Shoulda coulda. We all don't like to change, and we definitely don't like to spend money. Both are a huge mistake. I don't think a grow should be without an environmental controller unless perhaps it is using LED or CFL lighting, and even then it would be highly beneficial. And I've had one of my ballasts on the floor under my a reservoir for 5 years now. It's easy, just be careful. Kinda like mountain climbing. One slip and your dead, so just make not slipping your main concern at all times. The ballast will move soon though, if I can pull my ass out of my ass for once.

OK-I'm going to walk thru cable routing kinda quick.

This is all pretty straightforward. We'll start with the cord that's going to run from your ballast to your lamp.

Remember, this wiring is on the HIGH VOLTAGE side of the ballast transformer. HID bulbs operate at a nominal 600 volts AC ( which, as trivia buffs may be aware, was proven by no less than Thomas Edison to be capable of causing a watermelon to explode, properly applied. Thomas Edison must have really loved his job.). There's a very signifigant start-up surge when the bulb fires- Peak voltage is determined by the bulb's cold resistance factor, but it will be notably higher.:wtf:

(Please Please Please don't try to add length to your lamp cord by splicing in romex or an extension cord. They're not designed for this kind of voltage, and very likely to fail. You can buy the right stuff @ Home Depot, if you have to splice in. Or better yet, just buy a longer lampcord and socket set @ your local hydro shop, if you're not very very comfortable with appliance level wiring. F#$king up is a good way to start a fire or fry a ballast, though it does make for interesting fireworks).

So, from the above, we can assume that we want this cable run very neatly, with nothing pulling on it, up off the floor- so we can't step on it, and it will not get wet. It's a very good practice to make sure that you can't touch the lamp cord and any exposed metal plumbing ( pipes, radiators, etc) at the same time.

So, let's start by lowering your reflector down as low as you can ever imagine running it. Now lower it another six inches. Toss a ceiling hook in up by the existing hook that holds the chain running to the socket end of your reflector, and loosely loop the lampcord over this new hook. I generally put on a cable tie, very loosely, so that I can still slide the cord easily, but I know that it's not going to pop off.

Have you thought yet about where your ballast is going to live? Ideally, a the ballast does throw some heat, we'd like to have it out of the room entirely- but this might be overly complicated. If you've sized your ventilation properly, it'll handle the ballast heat just fine.

I've only got one hard and fast rule about ballast placement- IT MUST BE HIGHER THAN MY WAIST.

Why? Because five gallon buckets full of water are heavy, that's why.

Simple fact of the matter is that you will, at some point, be carrying a full five of something in this room. On account of being a primate and all, the easiest way to carry a full, heavy five is by the handle, which puts it down by your knees and out away from your body. If you're short on room, though, or if you need to pour from said five, you're going to rest the base of that five on your hip bone- and that's when you're going to drop it.

Growrooms by their nature pose a high risk of accidental intersections of electricity and water. There's a reason why building codes require a UL listing for water heaters and washing machines- and these are the only things that I can think of in the average home that bring water and electricity into the same proximity as a growroom. ( OK, hot tubs and fridges w/ icemakers... I'll be over around eight, have margaritas ready...).

I was once standing next to a 1KW halide ballast that got suddenly, catastrophically wet. About 8 milliseconds later, I was sitting a good ways away- then running for a fire extinguisher.

Seriously, keep your ballast up out of the spill zone- water and high voltage transformer plates do not play well together!!

So figure out where you're going to put the ballast, and string the lamp cord over to where it's going. I just use ceiling hooks, myself. Run the cord as straight as possible across the ceiling and then down the wall to your ballast. Ballast sitting on a shelf is fine, but I like to actually hang them right on the wall. Quality ballasts will have some kind of rigging hardware built in- keyhole slots in the handle, or a bracket on the bottom of the ballast. ( You may have to pop the rubber feet out.) I usually don't bother trying to acoustically decouple the ballast from the wall, but if the buzz makes ya nuts, slip a couple of neoprene washers between the wall and the ballast when you hang it.

Anyway, ballast on a shelf is fine- if you can spare the shelf space. I'd be really surprised if you can't find anything better to do with that shelf, though. Ballast on the floor, though... not a risk that, to me, is worth the benefits. ( Hint- there are no real benefits. You're just struggling with inertia).

Same thing with extension cords and suchlike- up off the floor, and ideally mounted on the ceiling. I in fact have, more than once, had an extension ground out through a puddle and then through me. The sensation is really indescribable, and you really don't want to find out.

Plug the lamp cord into the ballast, and gather any excess at that end into manageable loops. Use a cable tie to secure these loops to your last ceiling hook. DO NOT plug the ballast into power quite yet.

Now raise the reflector up to the highest level that you will ever ever use it, and figure out what you're going to do with the excess cable at this end. I like a bicycle hook that I can throw loops over as they develop. Make it easy on yourself- make it easy to keep things neat.

Go ahead and put your bulb into the socket, remembering to wipe it down when you're done. The oils from your hands can cause hot spots on the surface of the bulb, which could cause ( rapid, spectacular) failure. I just use a clean paper towel.

Ok, take a break, blow a bowl, and get some sunglasses.

Ready? High? Feeling sassy?

Go ahead and plug that sucker in. You deserve it. ( Now you know why you wanted sunglasses.)

I don't know about anybody else, but the sound of a ballast getting powered just makes me feel like a little kid. Seriously, all warm and fuzzy inside...:D

OK, next thing to do is cable in the fan, but I think that we should go over environmental controllers before we do that. There may be decisions to be made about where to plug things in, and it's helpful to know why. There are also some things to know about how the controllers work, and what they need to work well.

Now that I know that people are actually looking at this, and I'm not just typing into the wind, installments will come much more quickly.

:rasta:This is really good information! I learned most of it when working with marine aquariums.

----
reefkeeer: (ref-ke-per) n: individual obsessed with placing disturbing amounts of
electricity and seawater in close proximity for the purpose of maintaining
live coral reef organisms.
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Almost the same thing can be described for indoor pot farmers.

I did use a 15 amp extension cord to add a 4' lead to my ballast. More than 2 months and no issues, but I'm going to upgrade it ASAP. Any specific recommendations on what to use instead?

Another section that would be awesome would be completely light-proofing cabinets. I had (and to a degree, am still having) problems lightproofing my ClosetMaid (Home Depot) wardrobe.

Thanks for taking the time to write all this down for us newer growers! I don't think you really realize how many plants you've probably saved, and how much you're really helping to "overgrow".

Env. Controllers, at their very simplest, can be as simple as a thermostat that turns on an exhaust fan when temperature hits a particular setpoint. Most folks find that they outgrow that sort of rig pretty quickly.

Let's think about the temperature and humidity cycle of a room over a 24 hour lighting cycle. We'll assume that you're flowering at 12/12, and that the lights come on at midnight, which just makes the math easier. We'll use 24 hour military time.

At 0:00, your light(s) kick on and the room begins to warm. (If you just have a fan running on the same timer as your light, you may find that the coldest moment of the day is actually right after the light goes on, as the fan is sucking cold outside air into a room that's not hot yet).

By 1:00, the room is hopefully pretty warm, ideally at 70-75F @ an RH of 40-60%. Lovely.
If your fan is perfectly sized, it might even be kinda stable. More likely though, a slightly oversized fan is causing the room to run cool, or a slightly undersized fan is causing the temperature to slowly rise as the â?? dayâ?� goes on. The warmest point in the â??dayâ?� will probabley come near the end of the â??dayâ?�, around 12:00, when the light has been running for a long time and the outside temperature is going up.

Now we're in the dark part of the cycle, and temps are going down. Maybe.
Another scenario is that the fan has turned off, but the bulb and reflector are still hot. As the room's no longer being cooled, it's common to get a temperature spike before temps start going down.

As warmer air will hold more water vapor than cooler air per cubic foot, this temperature spike will cause a water uptake into the room's air- which is fine, until the room starts cooling down. As the room cools, the relative humidity goes up- and if it get's high enough, you can get dew.

The combination of high humidity and lower temperature will often cause mold problems.

So now it looks like we need to control both temperature and humidity, and we need to control them seperately from the lighting cycle.

The easiest, and pretty much cheapest, way to do this is with a purpose built environmental controller, like the CAP Air-1 or the Greenair CT-DH1. These units contain a thermostat and a humidistat that are each wired to apply power to an outlet when either temperature or humidity exceed preset conditions. They're designed to run an exhaust fan.

When you look at purchasing these, you'll be shocked at the cost- I was. Being a bit of a yahoo about making my own controllers ( I once rebuilt a Holley choke plate so that it could be controlled by a bicycle brake cable from inside the cab, as I was too cheap to replace the automatic choke element), I decided to build my own. A quick visit to the local electrical supply left me about $140 lighter in parts (humistat elements are wicked pricey), and then I spent a day figuring out how to paralell wire the two units. I should've just gone the $150-$175 for the pre-built, and I have ever since.

These units are the bare basics, and it's worth looking in the $200 range for feature sets that you think you'll be able to use. For instance, if you think that you're ever going to use C02, you'll want a unit that has an out let that gets switched off when the fan outlet gets switched on. You can plug your c02 timer or ppm controller into this outlet and be assured that you aren't releasing expensive gas when your fan is running. If you're using a cycle timer to control the gas, it'll reset to beginning of cycle when the fan goes off. Neat, huh?

I really love the Sentinal stuff- look at their EVC-1 at a street price of $200- very nice unit.

Anyway, let's go through the cycle again, but this time with a basic controller in place.

At 12:00, the light kicks on. The fan is off, so the room warms quickly to operating temperature. When it gets to the top end of operational range, the fan kicks on and cools the room to the low end of operational range. ( Thermostats use a built in hysterisis, or swing- the fan will come on a few degrees above setpoint, and go off a few degrees below- like your home heating thermostat in revere.)

The room continues this slight swing until the lights go off. If the room is warmer than setpoint, the room is cooled until it hits the low end of the range- then the fan goes off. The room will continue to cool until you hit the high end of your range for humidity- then the fan kicks on and flushes the damp air from the room. No dew- less chance of mold.

When you get into fancier controllers, they'll often have a â??night time onâ?� outlet- a built in photocell controls an out let that's only powered when the lights are off. Perfect place for a heater, if you need to use one.

If you have seperate temperature and humidity control outlets, you may choose to dehumidify with a dehumidifier rather than a fan, which doesn't cool the room. This makes it very easy to control low â??lights off tempsâ?�, or to keep inside humidity at appropriate levels when the outside humidity is very high. ( Think Alabama in August).

Your controller can also be used to run an AC instead of a fan- just watch out that your plants are getting enough fresh air or enough supplemental c02. Also, make sure that your AC isn't blowing unfiltered (stanky) air out into the street- most units can be set up so that they don't actually purge air, as it's more efficient not too.

An environmental controller is one of those investments where you get more from the third hundred that you spend than you do for the first two, and they scale up to larger spaces very well- think through your purchase, and buy all that you think you'll need for at least a couple of years. Going cheap and then buying better is often more expensive than just buying best to begin with.

When you mount the controller, make sure that it's exposed to good airflow- I like to actually have a fan blow over it. You want air from plant level, and blown over the canopy if possible. Mount it someplace where you can see it well and you won't jostle the knobs.

If you get a humistat wet, it's useless- either dead or so far out of calibration that it's effectively dead. Up out of the splash zone, as well as all associated power cords.

Hey, I'm sure people are reading and relishing what you've written so far. I still need to re-read all that you've said, but right off, I'd like to know how enclosed light-hoods affect your CFM ventilation calculations.

I made a spreadsheet with formulas so that I could goof with variables: room dimensions, feet of duct-work, number of 90 degree turns and such. Seems that your equations assume that the grow light is open to the room, rather than being hooded and ducted on its own, or in conjunction with the room's exhaust. I'd expect that if the heat did NOT leave the lamp and run all over the room, that it would be less of a problem to exhaust. It should be exhausted at its source (at the hood). This may lower the need for so many CFMs.

I'm planning two tiny veg and bloom closets (2.5 x 3 foot each, with 6-foot ceilings).

I'm going with a suggestion from stinkyattic I believe, to have my two grow rooms heat/cool each other by setting the light cycles out-of-synch between the veg and bloom rooms and exhausting one room into the other. Correct me if I'm wrong, but unless I get some solenoid-driven dampers to switch flow around as the lights cycle, it might be easier to just have an dedicated exhaust fan in each room, pushing one room's exhaust into the other. Of course I'd have some light-blocking feature so that the light would not bleed over between the veg and bloom rooms.

I'm thinking of just having both veg and bloom rooms exhaust directly through their cooled lamp hoods continuously, with their own dedicated can fan directed into a separate carbon filter. The outflow will be directed into the other room, and I'd adjust it if I see the temp in either room rise above 78F. The extra cost of duplicate fan and carbon filter will allow for some redundancy (e.g., in case one fan gives out), and the two carbon filters will last longer since there are two of them. But, two fans will use more electric power and add some heat on their own.

The other possibility is for me to include ductwork INTO both enclosed hoods and exhaust them without any carbon (odor) filtering. This would draw clean air into the light hood, past the lamp, out of the hood and out of the grow room. I'd ONLY filter the air from the ROOM itself (the air that is in contact with the plants). This is more complicated than I wanted to get, but is an option if I get some consensus here or impetus to pursue it.

What do you think? How much would directly handling the heat from the lamp/hood change the required CFM to properly ventilate a grow room (or specifically, a veg and bloom room exhausting into the other room)?

I'm more concerned about the NOISE of the fans rather than the added cost of two fans to exhaust the two rooms. If I think long enough, maybe I could figure out how to do it with one big can fan instead of two smaller ones. But again, stealth dictates for me to go with less noise.

My guesstimations absolutely assume that the hood is not cooled- There are just too many variables regarding reflector design to make any kind of meaningful guesstimates.

Could you post up the spreadsheet somewhere? It might save folks some work. Great idea.

I'd probabley just circulate between the two rooms with a couple of 6" muffin fans. You can pick up " starter flanges" intended to run 6" round off of box style manifolds for forced air heating systems- If you mounted one @ the top of each room, w/ the fan blowing thru the partition, thru the flange, and into some 6" flexi that leads down to floorish level in the other space, you'd get a nice flow pattern and built-in light proofing. Should be pretty cheap if you go Rat Shack for the fans. I def wouldn't screw w/ duct solenoids @ that level- too pricey, too complex. Neat, though...

If airflow between partitions is good enough, you can just put the filter wherever's conveniant. You could also use one fan on the exhaust, w/ a y-splitter on the intake and maybe an odorsok in each space.

Don't forget that on-time in veg will be longer than in flower, so there will be an overlap period when both lights are on.

I would def recommend using a ventilating the lights seperately- suck in clean air from outside, blow it over the bulbs, and outside again no filter. Just make sure that all of your joints are airtight, so that you aren't picking up stink from inside. Use the aluminum tape- duct tape will go soft at temperature. Seems more complicated, but it's actually simpler, as this fan is set&forget, and it takes a lot of load off of your main vents. Doesn't have to be much of a fan for a couple of 400s. If'n your feeling sassy, you can stick this fan on a thermostat, which turns it off if temp goes low- allows you to set a temperature floor.

The fans for inter-room exchange and yer hoods should be pretty quiet- the only noise issue is the primary exhaust. You can cut noise by using a larger fan on a speed control- fer instance, you need a 4", but you go up to 6" and cut the fan speed in half- greatly reduces noise. You'll also find that you can tune the sound of the ductwork by varying it's length- imagine a pipe organ.

Sorry I can't be more specific about hood flow interaction, but there are just too many variables, including changes in ductwork length/shape as the hood moves up and down, to make big sweeping statements. If you can be more specific about the hoods involved, I can tell ya what I see...

Hope this helps.

Quote:

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Originally Posted by MaryLane

Great thread! I'm learning a lot. Now you need to do one on cabinet growing. :)

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^^^^^

Thanks for confirming that some of the things I've been planning (and didn't mention) are in agreement with your suggestions, and for the following ideas:

1. I'll look into the washable carbon filter, Odor-Sok.

2. For the exhaust/odor-control, I'll use a speed-control to cut the RPMs of a larger fan, thus reducing the noise (as compared to a smaller fan blowing full-tilt!).

3. It hadn't occurred to me that a muffin fan running continuously can move a lot of air between the two closets. And when you consider that a small muffin fan cools a PC which uses 200-250W, a muffin fan would probably cool the enclosed lamp well enough.

What CFM would cool a 400W enclosed HID lamp if the ducting were simply straight through (with just 4 feet or so of ducting)? I can use your exhaust formula to take into account the true loading: 3 to 4 feet of flexible ducting, either:
a.) entering and exiting the TOP of the closets (to avoid two 90-deg turns had I cut holes in the closet SIDES) snaking down, entering/exiting the lamp, then up/out, totally to 6 to 8 feet while making only two 90 degree turns, or
b.) entering and exiting the closet sides, with two additional 90-deg turns, as compared to situation a.) above.

I'm not committed to a particular type of hood yet (I'm still planning my first grow!). I'm thinking about a home-made glass bake tube, or perhaps will spring for a store-bought enclosed hood with a large reflecting surface.

Oh, and I'm working on finding a safe place to upload the spreadsheet with all the exhaust-loading formulas entered. Any suggestions to protect my anonymity and security, while still sharing the file?

Look at SuperSuns from Sunlight Systems- they're discontinued now, but they had a really unique air cooling arrangement that might work well w/ your layout. Nice little footprint, too. I'm sure somebody out there has a couple in the back, still- or you could call Sunlight and see if they can help ya find some.

The SuperSun, not the SuperSun II.

Are we talking one muffin per reflector or one muffin running both, with ductwork interconnect? If we're talking one per reflector, I would just grab whatever is cheap and easy in 6" muffin- it'll do ya, go w/ any reflector that's got glass and 6" flanges.


If you wanna run two fixtures on one fan- muffins won't cut it.
You've got a fair amount of duct drag, so fan design gets to be an issue- if yer going 4", you'll probabley need more than a muffin, regardless of free-air cfm. Even @ 6", tho better.

Guesstimate that 70cfm throughput is gonna be overkill, depending on exterior temperature. Overkill here isn't a bad thing- you can always dial down.

I'm sure a 4" in-line would be more than enough, even dialed way down.

Have a look at bathroom exhaust blowers down @ the depot- they might have something cheaper than a grow-store inline, since you don't really need all that high a SP rating- but more than a muffin.

Ya might wanna flow it so that heated air moves from flower to veg- if it runs a little warmer in veg, it's not the end of the world.

Quote:

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Look at SuperSuns from Sunlight Systems- ...

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I'll look at the SuperSuns (as I can find 'em), not the SuperSun II.. tho I'm having a problem Googling 'em. And I'll look at some bathroom exhaust blowers.

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Guesstimate that 70cfm throughput is gonna be overkill, depending on exterior temperature.

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This will be a basement grow where temps are maybe 65-70F that time of year. So, I figure there is a giant heat-sink in the basement to dump any excess heat. I think I appreciate when folks say, "Basements rock!". With minimal basement exhausting, and perhaps some kind of CO2 enrichment (or more accurately, some CO2 remediation) I'll be fine. I wish I could measure/monitor the CO2 cheaply.

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Ya might wanna flow it so that heated air moves from flower to veg- if it runs a little warmer in veg, it's not the end of the world.

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I can appreciate that the temperature in the bloom closet is much more important/critical than that in the veg room.

I'll try to post about my plans, otherwise I'll post some kind of log here. I've really learned a lot here so I feel that most of my plans will get a few nods (if not a few nod-offs!).