4'(h)x4'(l)x2'(w) AF Cab Design

[TheGreenBastard]

After ~15min in Blender I came up with this:


Click to Enlarge

Cab: 4 feet high, 4 feet long, 2 feet deep

1) intake (~100sq. inches)-
1x 120mm fan (~5"x5") active intake
1x 6"x12" passive intake

2) exhaust (~50sq. inches)-
2x 120mm fans (~5"x10") to filter

Lighting: Unsure

Containers: 18x 16"(h)x8"(l)x8"(w) = ~4.5gal

Strain: Sour 60

I'm looking for any suggestions on lighting and ventilation, the fans mentioned are 120mm Delta PC fans which are rated @ ~100CFM each (I have 3). I proposed using one as an intake which would run across the lights to reduce heat and increase the total intake area. I'm not sure if this is a practical move or if I would be better off using a bigger single intake. I feel that these fans will be enough to setup a negative pressure system even with a filter (which will probably be DIY) though due to my generally limited knowledge in fluid dynamics I'm unsure if this would be adequate.

 

[TheGreenBastard]

CFL Cab

CFL Cab

If I were to use CFL's it would look like this:


Cylinders = 4x 55w PL-l's
Cones = 4x 42w CFL's


I originally wanted to use only 220w of PL-l's but changed the dimensions so I wasn't sure if it would cut it. That's why I added the four CFL's in the image. This setup would produce ~32,000lm (4000lm/sqft.) @ 388W (48.5W/sqft.).

 

[TheGreenBastard]

HID Cab

HID Cab

I will most likely use this design:


400w HID

The red box at the top represents a 120mm fan for cooling the bulb.

 

[Granger2]

Bastard,

You can try the pc fans, but I really don't think they are even close to the task. 338w of cfl should be enough [42 w per sq ft], but there will be considerable heat. I have a 2x4x6.5 space with two cfl lamps totaling 325w, and there's more heat in there than in my 3x3x6.5 stalls with 600w air cooled HPS lamps. Keep us informed on your progress. Good luck. -granger

 

[TheGreenBastard]

The cost of setting up the CFL's will be about the same as a 400w so I'll likely go with that.

Are you certain these fans won't be able to handle this space? The fans are rated at over 100CFM each, that is pretty substantial for a 120mm fan (delta makes some of the best PC fans on the market). The total volume of the room will only be ~32 cubic feet and the pots will take up almost 9 cubic feet so the fans will actually only have to move ~24 cubic feet of air. In that situation it seems like I would have to worry more about moving too much air (too many ACPM).

If air flow is uninterrupted and I use all three fans (321CFM) as exhaust with a large intake it would theoretical have 10 air changes per minute. With the 9 cubic feet taken up by the pots the ACPM would rise to ~13.375. Ideally you want your air changed about every 5 minutes, so it looks like a have plenty of raw air flow, now I need to determine how much I need to cool a 400w and push through a filter. Based on RedGreenery's thread it seems like I have an adequate amount for both.
(This is based on my limited understanding of fluid-dynamics, please correct me if I have made any mistakes or assumptions)

 

[Derka]

I am a huge fan of both delta and scythe high volume fans. However, I need to point out that by the time you purchase 3 fans, and the appropriately sized wall wart, you would have most likely exceeded the cost of a budget inline or squirrel fan blower, which would provide more then sufficient air pressure to both filter the air and create the vacuum inside the box.

 

[TheGreenBastard]

Damn, I was going to alter the deign a little but after upgrading to Ubuntu 11.10 from 11.04 my Blender 2.59 project files got deleted. At some point today I'll redo it with my new design idea, it should take ~10min to put it together including lighting and rendering I just don't feel like messing with it now (its smoke a bowl and watch some Fringe time).

 

[TheGreenBastard]

I am a huge fan of both delta and scythe high volume fans. However, I need to point out that by the time you purchase 3 fans, and the appropriately sized wall wart, you would have most likely exceeded the cost of a budget inline or squirrel fan blower, which would provide more then sufficient air pressure to both filter the air and create the vacuum inside the box.

Oh sorry, I don't know if I mentioned that I already have them, they are sitting on my workbench right now. I used to use them for cooling my CPU during really high overclocks (4ghz+).

I actually got them for free, they were in the garage of this house I moved into back in Austin (along with some other equipment, my landlord was defiantly growing in that house at some point).

EDIT: I forgot to mention I don't need a wall wart DC adapter, I have been using an old PC PSU, once hotwired it is just a massive 12v adapter.

 

[qupee]

I am a huge fan of both delta and scythe high volume fans. However, I need to point out that by the time you purchase 3 fans, and the appropriately sized wall wart, you would have most likely exceeded the cost of a budget inline or squirrel fan blower, which would provide more then sufficient air pressure to both filter the air and create the vacuum inside the box.

This is good advice.

Also, you may find a 400w hid doesn't throw much light all the way to the ends of your 4 foot wide cab. And you'll have a hell of a hot spot directly under the bulb in comparison.

You could consider PL-L flouro's they'd fit nice in that 2 feet of depth and you could create a very bright consistent lighting all the way across. It would push you towards scrog however, so maybe not what you want. Just another option.

 

[TheGreenBastard]

yeah, my biggest concern with the 400w was spread, it's been a long time since I've run an HID of that wattage and that was in a small closet back in highschool. I've been thinking of making a compromise on the width, it seem that 3x2 would be much easier to manage while still maintaining a decent grow space. I'll be running AF's so I really don't need much floor space, root depth is more important to me than anything.

I have defiantly been considering the PL-L's, I've used them in the past and would love to use them in this cab though I have to start from scratch so the cost would be equal to or greater than that of a 400w HID with less light. And while it does distribute light better, multiple heat sources become more difficult to cool. If I could find a reflector which would be capable of casting an HPS effectively over 3ft+ I think I could get away with it, if it doesn't look like it will have enough light I'll add some spiral CFL's to the ends of the cab which will later be replaced with PL-L's. Along with regular plant movement and rotation I think I could have some decent results, granted it will require a little more care.

Mind that this is all in the early stages of development. I want to get a solid, finished design down before I begin any construction. At this point anything is subject to change and open to suggestion.

 

[qupee]

I can say a 400w in a Sun System 1 throws a great square footprint over 3x3.. not that that helps you tremendously. I know the 250w I use for veg sucks hard at covering a long rectangular space and I'm extrapolating from that when I question a 400w and 4' length.

As for PL-L's, you could easily pack 10x55w in 4x2. I hear you about cooling, but a row of pc fans can cool the nice slim pl-ls across the length of a rectangular cab. You know of ahsupply dot com for packages with reflectors I assume?

 

[TheGreenBastard]

Yeah, I've looked into those but if I were to go the PLL route I would build it myself using centrum advanced ballast. The problem with that is 110w's cost ~$60 to setup, multiple that by say 4 and it begins to exceed my budget. If I were to go with floro's I would need several CFL's to supplement the PLL's, which is where the heat becomes an issue. If I can find a good deal on PLL's and/or my budget increases they we definatly be bumped to the top of the list.

BTW, the reason I wanted to run a 400w rather than a 600w which might do the job (if i could handle the heat) is that I wanted to eventually replace the bulb with a CMH and supplement with PLL's. I'm also starting to consider two 250w's, solves two problems, more watts and more coverage (cooling shouldn't be too bad either).