Scrubber has to be a cylinder?

[diamondmine]

Does a carbon scrubber have to be made in the typical cylinder shape to work or can it be flat? I want to make a box and one side will be the filter, so the filter would be flat, kind of like using the top of a shoebox. I don't want to waste my time though if it won't work. I realize the cylinder design has more surface area but it would be better for me to use a flat filter.

 

[FreezerBoy]

Flat works fine. Here's the only one I can think of right now: Panasonic Whisperfans

While 100 pounds of carbon will last longer than 2 pounds, 2 pounds may well last through an entire grow. So you replace carbon every grow rather than every other year. This is common to many things in micro grows; The smaller the res, pot, filter the more maintenance they require. Just the cost of doing business.

 

[ScrubNinja]

Yup flat works fine. Here's one I made



Be sure to have no gaps or leaks of course. Be sure to wash the carbon first or it'll be dusty. I used 2kg of activated carbon, and I'm on my 3rd grow with it now.

 

[jimbo99]

i did a flat one years ago. It worked, but not as good as the cylinder ones. I used it for my first grow because i was being cheap and didnt wanna spend money on the proper equipment. I bought a vortex and built a cylindrical one for my next grow. Heres some pics of how i did it.

 

[BlindDate]

Flat or round is the exact same thing. It just has to do with the area of the filter and the thickness of the carbon bed, not the shape of the filter.

jimbo99...From that picture it looks like your carbon bed is only 1/2 inch thick. Maybe that is why it did not work.

 

[diamondmine]

Excellent that's just what I needed thanx. I'm using a DIY lasko, disassembled and attached to a 2 foot tube(made from rubbermaid garbage can) that lays on the ground. All your ideas are great and I also found great ideas in Freezerboy's link.

 

[diamondmine]

I'm using the Lasko/Stanley blower which I think with a scrubber is around 150cfm, so would my flat scrubber be around 10 inches square according to this formula? -

Found this in DIY scrubber for dummies by Durbanpoison-
To figure out the size filter you will need for your fan, use this formula:
[If you need a larger diameter filter than listed in the tutorial, then you need to upgrade the duct sizes in the list and update the instructions.] Also keep in mind that if you're running some ghetto fan, expect ghetto results. Spend some decent money on your fan and it will perform. Some cheaper fans will give inflated figures too as to what the true CFM ratings are. My sig has a link for great pricing on vortex fans. I'm using the 4" 175CFM.

D = Diamter of Filter Inner Core (Inches)
H = Filter's Height (Inches)
I = Inner Core Surface Area Square Inch

CFM D H I
150 4 9 113
200 4 12 151
275 6 12 226
375 6 16 302
400 6 24 603
550 8 24 603
650 10 24 754

See the relation there?
Just take the CFM of your fan and choose the diamater of core you want and divide it accordingly. For example: I have 175 CFM and intend to use a 4" Diameter core. So I can look at the list above and figure;
150(CFM) divide 9(H) = 16.6 (Approximately)
Then I can take my 175(CFM Fan) and divide it by 16.6 to get 10.5". Therefore, my 175 cfm fan with a 4" Diameter would need a core height of 10.5".

 

[FreezerBoy]

jimbo99...From that picture it looks like your carbon bed is only 1/2 inch thick. Maybe that is why it did not work.

Could be. Speaking ONLY for myself and my 1 plant grow, a 1/2" bed has lasted through 3 grows now.

 

[diamondmine]

Could you guys tell me the length and width of your flat scrubber, approximately? I'm looking to make mine 12"x12", so 144 square inches. I'm using the stanley blower so I hope that size will do.

 

[ScrubNinja]

This is very approximate but I'm around 310 sq inches, about 1/2" thick of carbon, 220w of fluoro, and a fairly low end computer fan pushing (I use the second "pulling" fan in summer).

 

[diamondmine]

O wow really, 310 sq inch and only a computer fan. Hmm, I'm not understanding the chart from DIY scrubber, maybe I should just ask in that thread.

 

[ScrubNinja]

Yeah not too sure mate. One thing I can say though - with a pc fan, the more surface area you have, the thinner your layer can be, to a point, because the air is moving slower through the larger area of carbon. Since it's thinner, the fan pushes through easier too. So it's generally an exponential improvement the bigger the area you use.

Usually pushing too much air is not a problem with these fans, and if it was, I would just sprinkle some more carbon on top - a great benefit of flat style filters - they can be "tuned" easily if you need.

 

[diamondmine]

Yea I'm kind of stuck with this stanley blower, I don't know what dimensions to make the filter because if I go too small then it won't work but if I go too big I can't afford 20lbs of carbon. The stanley thread is helpful but everyone in there seems to be using ALOT of carbon, some had over 20lbs.

 

[diamondmine]

I think this "simple scrubber" by Haps will work- http://www.icmag.com/ic/showthread.php?t=39506
He's using a 750cfm fan and pushing through what seems to be a 10" filter with about 3lbs of carbon, so I think the stanley blower will work with this.

 

[ScrubNinja]

I'm using the Lasko/Stanley blower which I think with a scrubber is around 150cfm, so would my flat scrubber be around 10 inches square according to this formula?

Hold up, I just saw the question. How many CFM does your fan push with no filter? That is the number you should use with that table I think. Basically match the cfm, and the area, and make the carbon 1" thick, and you will be in line with that table, if that's what you mean. Like your area planned for a flat filter is close enough to 151 sq inches, so if your fan was 200cfm, and your carbon is 1" deep, it should match up. It's late here so forgive me if I misunderstood what you're getting at.

 

[diamondmine]

Yes that's correct. I'm guessing the fan is around 150cfm, that's on the low setting which I plan on using. I've read through the stanley thread a million times and the numbers seem to range from 150cfm to 300cfm for that fan. It's seems that the chart is telling me that 150cfm should have 113 square inches so I was going to go bigger, now I'm thinking a 14 inch square which would give me almost 200 square inches. Btw I plan on using 3 pounds of carbon because it's all I can afford. I think it will work because it seems to be working in the thread I posted above by Haps.

 

[Haps]

It took me a couple tries to get it right at first. Main thing is flow through, if the air goes through the carbon, it will work, good luck.
H