Anti's MicroStealth Cab 4000 (The PL-L adventure!)

Anti · Jul 6, 2010

Ok. I'm tinkering in sketchup again:

(Click to see full-size)

Basically what you're seeing is three 18" 50w PLL being mounted vertically in the cab. (Not yet sketched fully in, but hinted at are 3 PC fans which would mount directly above each PLL and pull all air from the cab through the "cool tubes" around the PLLs.)

The yellow and orange circles on the bottom of the cab represent light penetration. The inner circle is 3" away from the bulb and the outer circle is 6" away from the bulb. Every part of the cab is within 7-8 inches of a bulb!

My thinking behind this is basically this:

a 50w PLL puts out 4000 lumens at a distance of one foot. Because of the inverse square law, this means that at a half foot from the bulb, (the orange circle) it is putting out 16,000 lumens. per sq ft. At three inches from the bulb (yellow circle), it would be putting out 64,000 lumens per square foot.

A decent percentage of this cab is within the yellow circles and almost ALL of the cab is within the orange circles. (Even segments outside of the orange circles are only BARELY outside of it, meaning that those segments are still getting more than the 4000 lumen per square foot the bulbs are rated at.

I guess what I want to know is: does anyone have any suggestions on how to improve this light print?

I am also considering building a cab that will have a 150w-400w HPS in the center and 50w PL-Ls in each of 4 corners.

Looking for input on either idea, really.

Major goal is to reduce footprint of current cab for stealth purposes while maintaining or increasing yield and nug density.

twrex · Jul 7, 2010

This looks wonderful, you're talking about nearly all the ideas I had floating around in my head. I can't wait to see where this ends up. My own personal take on it was that I liked using 6x36w pll off one workhorse 8. My reasoning was this would distribute the light better throughout the cab and allow for more spectral customization with temperature mixing. Also, for a perpetual grow I had an idea about making the entire cabinet a gradient from higher to lower kelvin temps so that as the plants matured they could be moved from one side to another and be exposed to more and more red light.

Although it's a bit hard to see my attempt at sketching things up placed the lights around the perimeter in in a staggered pattern to help spread the light out.

https://www.icmag.com/ic/picture.php?albumid=18758&pictureid=388756

Anti · Jul 7, 2010

thanks for your thoughts. I'm going to keep experimenting for now, but I did consider a design that would utilize 4 pl-ls in the corners and 2 in the center. Basic issue is that I am trying to keep everything within 6" of a bulb or closer. A 250w HPS puts off about 20,000 lumens at a 1ft. distance. If you can keep everything within 6" of the PLL they get pretty close to that 20,000... 16,000.

That's why I was considering an HPS for the center with PLLs around the edges to brighten up any shady spots.

I do like your idea of varying the kelvin from one side of the cab to the other.

Come on, people. Let's revolutionize micro growing!

MrAwder · Jul 7, 2010

Hey Anti

I must say your original cab was a huge inspiration to me and the cab I have going now. Of course, we can never be completely satisfied right? Well I was messing around with a similar idea, although slightly larger scale, and thought you might like to see my design. Here is the link: https://www.icmag.com/ic/showthread.php?t=178828 With the final design being post #4. The only real difference is that I have the "cooltubes" for the PL-L drawing directly from their own intakes, separate from the growing area. This is because I am concerned with maintaining high enough CFM to cool everything while pulling through a scrubber.

Currently I'm running a corner cabinet in a similar style, but passively cooling the lights along with the rest of the cab. It's working okay but I'm not at all happy with it. Mostly because my carpentry skills are awful but I also made some poor design decisions. Thus the redesign.

Here are some pics:

The main issue is not enough center light, so temps permitting I am going to add in either 2 42W CFLs or 4 23W, just hanging from an extension cord. This should get me through a few harvests until I have the cash on hand to start the new project.

Now to be honest, I love the PL-L lights, but I am really considering investing in LED. The price is somewhat prohibitive, but the low profile, low heat and great efficiency just cant be overlooked. Basically it would be the same dimensions for the cab (the linked one), but 2 126W LEDs and 4 modular scrogs instead of what you see in the other design. But at that point your talking $1k just in lights.... bah.

anyway sorry I rambled a bit, just wanted to add my .02 to the discussion. and thanks again for being such an inspiration to us micro growers.

twrex · Jul 7, 2010

oh man, I'm totally diggin' the corner cabinet!

stink.whistler · Jul 7, 2010

The vert. tree growers want a light pattern with three lights hitting each plant. X= plant O = light:

OXO
XOX
OXO

Could you go with a square cab, or are you definitely going rectangle for the method you have selected for stealth?

One complication, I would think for access purposes my little diagram above would require at least a door in front and a door in back, or it would be a real pain to get at the back plant.

twrex · Jul 7, 2010

stink.whistler said:
One complication, I would think for access purposes my little diagram above would require at least a door in front and a door in back, or it would be a real pain to get at the back plant.

Tilt and I talked about this once before and it seems like using carflex flexible tubing at the top of the vertical cooltube should allow the lights to be easily moved out of the way for plant access.

Anti · Jul 7, 2010

stink.whistler said:
Could you go with a square cab, or are you definitely going rectangle for the method you have selected for stealth?

I could theoretically go for a square cab, but my current cab is like... 4ft wide by 2.5ft deep. I'd prefer to keep any future cabs under 2ft deep. By making this one 1 ft deep, I only have to worry about light penetration on one plane... if I made it 1.5 ft deep and kept the lights in the center, there'd be 5+ inches to either side of the light in less than 6" proximity to the bulb... or I'd have to add more bulbs.

If I add more bulbs, I would prefer to widen the cab and leave the depth alone.

All of the above designs are 4 sq ft (most are 4ft x 1ft) except the last two on the bottom row, which are 3.5ft x 1ft

If you take a look at this figure, you can kinda watch my thought process. The one with the red arrow is the one you see in my first post.

I am not Mr. Know-It-All when it comes to lighting or plant growth. I am looking for any and all recommendations.

twrex · Jul 7, 2010

the problems that I see with this analysis are:
a) you are limiting yourself to placing your lights around the very edges or in the very center, I believe putting them 'in' just a bit to allow the plants room to grow around the lights is better. (you'll see this in my cab design if you look at the placement on the top shelf)
b) you aren't factoring in reflected light from the walls or overlapping light zones which are places where the plant will get EVEN MORE light.
c) nitpicking here 3.5ft*1ft != 4sqft

Point (a) is certainly the biggest problem I see with your methodology here, by adjusting the lights' positioning into a staggered setup you can maximise your light penetration and coverage and more effectively utilise your lights. Maybe if I start feeling froggy later I'll do a few mockups intensity maps of my own.

Anti · Jul 8, 2010

twrex said:
the problems that I see with this analysis are:
a) you are limiting yourself to placing your lights around the very edges or in the very center, I believe putting them 'in' just a bit to allow the plants room to grow around the lights is better. (you'll see this in my cab design if you look at the placement on the top shelf)

I went with center because it keeps the largest portion of the cab lit consistently.

I'm really leaning toward trying a small HPS (like 250w?) with (4) 50w PLLs around the edges.

No firm idea yet. Still in concept stage... but I saw that I can get as many workhorse 8s as I want (which according to fulham can be wired up to (4) 50w plls each) for like $30 each.

Please nit-pick all you want. Beat some sense into me.

b) you aren't factoring in reflected light from the walls or overlapping light zones which are places where the plant will get EVEN MORE light.

I don't really know how to realistically factor in the reflected light. If they were in the corners those corners should have a LOT of reflected light since all light coming out the sides facing the walls would be almost instantly reflected, but some of that light might be converted to heat in the process and I don't know how to account for it. Anybody know a formula?

c) nitpicking here 3.5ft*1ft != 4sqft

I know. 3.5*1= 3.5sq ft. If you look right under the last image you'll see "all of these designs above are 4sq ft except the last two which are 3.5 sq ft."

Point (a) is certainly the biggest problem I see with your methodology here, by adjusting the lights' positioning into a staggered setup you can maximise your light penetration and coverage and more effectively utilise your lights. Maybe if I start feeling froggy later I'll do a few mockups intensity maps of my own.

Please do. I need other minds on this at this stage. Thanks for your help.

stink.whistler · Jul 8, 2010

Anti said:
...

I'm really leaning toward trying a small HPS (like 250w?) with (4) 50w PLLs around the edges.

...

Having the equivalent of 5 of your fluorescent lights concentrated in a single bulb means a serious concentration of heat.

Are you thinking of a cooltube, or are you willing to give up some space in your cab by keeping a dead area around the bulb?

cooltubes seem a pain to stealth in plain sight (is this a goal? similar to your existing cab?)

Anti · Jul 8, 2010

stink.whistler said:
Are you thinking of a cooltube, or are you willing to give up some space in your cab by keeping a dead area around the bulb?

Yeah. I'd be definitely cooltubing or otherwise venting the 250w. Any cab featuring HPS will NOT be cooled by PC fans alone.

cooltubes seem a pain to stealth in plain sight (is this a goal? similar to your existing cab?)

Definitely a goal. Thanks for the heads up.

Here's something I just mocked up for your perusal:

This is a 3ftx2ft idea with a 250w hps in center and (4) 50w PLLs on sides.
*16,000 lumen @ a distance of 6"

The HPS has a 12" band around it since it is bright as hell for 12". The PLLs are still 6" bands because beyond 6" they quickly lose their ability to compete with the HPS.

Anti · Jul 10, 2010

Ok. Here's another idea. I like this a lot.

(2) workhorse 8 ballasts ($60-80 for both w/shipping)
(8) 50w 3g11 PL-Ls in "floro-cool tubes" ($80-$100 w/shipping)

That's 400w of PLL stretching from ceiling to soil within 6" or less of anything in the cab.

This would be a 3.5ft x 1.5ft (5.25sq ft) interior dimension cab that stands 30" tall. The light setup means the parts of the cab that are FARTHEST from a given light are only 6.5 inches or LESS away from the nearest light! anywhere in the cab!

The yellow circles on the top represent the 6" point from the bulb, as in most other examples.

If I can get the space above the lights (where the "cool tubes" exit) air tight, I'm thinking I can put a carbon layer above the lights with one decent extraction fan (not talking PC fans for this one). If I put the fresh air vents near the top of the chamber (a reverse of my current design) I can still do a light proof baffle and have my passive intakes at the bottom of the cab.

I'm thinking that the cool tubes around the lights can extend almost to the bottom of the cab and thus pull air from outside through the cab, over the lights and then into the carbon layer on its way out the back.

I'll try to work on my model and give indicators of what I'm talking about here in the next few days.

Cabinet construction will be beefed up for this cab based on what I've learned from the 3000 model.

Anti · Jul 10, 2010

Same design as above, but I measured out the available space around the bulbs. If I went with the same size containers I'm using now, I could pack 82 in there. (the dark areas represent wasted space, but in reality would be distributed evenly among all plants so each plant had a little breathing room from its neighbors.)

My current averages with 252w of CFL on the top are about 4.2g-5.3g per plantlet (dried bud) in this size container. With the vertical PLLs and the concentration of them, the light penetration from top to bottom of cab should be much more intense resulting in bigger, better buds with more weight all the way down to the soil.

Thoughts are welcome.

Garuda · Jul 10, 2010

Great idea using the fluoro-tubes as air intake :top: this should work perfectly. Simple but effective. Never thought about that, thanks.

Greetings,
Garuda.

stink.whistler · Jul 10, 2010

Anti said:
...

I'm thinking that the cool tubes around the lights can extend almost to the bottom of the cab and thus pull air from outside through the cab, over the lights and then into the carbon layer on its way out the back.

...

I used a somewhat similar method for carbon scrubbing in an old wardrobe grow and it worked well - I cut a 12x24 hole in the top, laid a furnace filter over it, poured about an inch of carbon on top of that, set another furnace filter on top, then wrapped the edges with cardboard and duct tape. I then vented the chamber to the back with a 4 inch fan (kind of like a PC fan, but thicker and AC, I think it was 80CFM).

Also, when I first saw you were using 4 50W bulbs with a workhorse 8, I was worried that was too much (I knew you could only use 3 55W bulbs with a WH8) - but you are right! You can use 4 50W bulbs, good design decision.

With that much wattage in a small box your needed fan capacity is such that it will make a good deal of noise for something sitting in your living room. My fan was only taking care of 150W and it was too loud to be out in the open like that. Mufflers need to be fairly large to make a big difference, not sure you have the space.

What is your plan for covering / explaining the noise? Freezerboy has a thread where he was trying to quiet a fan down enough to stick in a garage based freezer grow, and he had a great deal of trouble.

I am thinking your requirements for sound levels are going to be much more stringent than his, to me that is your biggest/most difficult problem to solve.

My personal opinion is lower the wattage down to closer to 50W per square foot so you have less heat to extract and can use a quieter fan.

Anti · Jul 10, 2010

My current cab is cooled by 3 PC fans which are running at anywhere from 1/2 to 3/4 power depending on the season. There are 80 cfm fans that operate at 0.3 Sones. The wiki claims that a "very calm room" is somewhere in the range of 0.15-0.4 sones. Normal talking from a meter distance is 1-4 sones.

I know that air noise and back pressure on the fans will increase the sound, but this is not something that will be in the living room. Also, since the entire cab would be about 13 cubic feet, the fan would probably never have to run at anywhere near full power.

Perhaps there is something else I'm not considering here, and if so, please clue me in.

If it proves insurmountable I could always dismantle the whole thing and use the extra lights for something else.

stink.whistler · Jul 10, 2010

I hope this works, I'll do something very similar if it does.

I assume you are thinking of having a chamber on top of the whole thing that vents out the back? Where are the intake vents? Will this be up against a wall? What is the stealth plan, i.e. what is the excuse for the big box sitting in the room?

My plan is high counter top (like in a lab) cabinets with 'my server farm inside' to explain the ventilation and noise. An electronic lock on the door, to avoid any visible locks. A small laptop inside with a monitor/keyboard on top of the counter top that really will serve as my audio media server.

Olum · Jul 10, 2010

I'm a big fan of your work Anti. I'm in the process of building a cab based off of your Microstealth 3000. https://www.icmag.com/ic/showthread.php?t=180952

MrAwder · Jul 13, 2010

still following along here. do you have any idea what fan you were planning on for this? seems like a S&P100 or Panasonic Whisper Fan would work. I do think that if you draw up air thru the tubes for each light from outside the cab, and you make sure the top compartment is air tight, then just straight exhaust it with a quiet PC fan. Then exhaust the chamber with a fan/scrubber in a separate air loop where you can afford lower CFM since the heat is already dealt with.

is this also going to be an all in one cab like the 3000?

Anti's MicroStealth Cab 4000 (The PL-L adventure!)

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