Are computer fans strong enough to pull through a small carbon filter?

exabits said:

You can look at the data specs, http://www.delta.com.tw/product/cp/dcfans/download/pdf/PFB/PFB120x120x38mm.pdf , I know how much air it moves, I know the air pressure it can exert and I know how loud it gets. Are you out to be mrThreadwarrior? If I get banned for this post, I don't really care, look at my post count... You said your own fail. Delta is the only company that makes a pc fan that powerful. If you didn't have a delta then your fans were shit, it's that simple. I don't know how many decibels a 4" inline is but I know my 6" is roughly the same a delta. Sound can be dampened and reduced. How many people here have sound reducing techniques? You keep argueing your opinion about your fans.....until you own a Delta UHE you shouldn't even comment about how your fans couldn't hack it and no other pc fan can either. It's simple science, this delta http://www.frozencpu.com/products/81...?tl=g36c15s562 fan moves more air then a 4" inline such as http://www.htgsupply.com/Product-Inline-%204in-Fan-by-CAN.asp

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Have you used one? Pictures of your setup?

Sure, why not... Here is 3 150cfm deltas pulling air through a xspc 360 radiator for my water cooling in a corsair 800d pc case.

So because they pull through a radiator you think a carbon filter is the same thing? Ok, this is when I stop discussing this with you.

What kinda cpu are you running to need water cooled?

Theres no need to debate this anymore. Go read the pressure specs, the guy can make his own educated decision.

OP get a proper fan dont mess about with pc fans. wireing pc fans to chargers is asking for a fire chargers get hot left on continuous im speeking from experience.

to be honest, im looking for a decent priced option to pull air through a small filter that ill make and will be quiet as the cabinet may go into either my computer room or garage. both options it needs to be as quiet as possible to reduce suspicion

praiseodin said:

to be honest, im looking for a decent priced option to pull air through a small filter that ill make and will be quiet as the cabinet may go into either my computer room or garage. both options it needs to be as quiet as possible to reduce suspicion

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4" RVK and fan speed controller = peace and quiet
And if you decided to go a bit bigger you have a good fan to start with.....

I recommend the pc fans, only because this is a stealth grow with very limited space. Sticking a 4" inline in your grow cabinet doesn't really even seem like a option to me. If it were me I would get 4 delta's and run a 4 into 1 for the purpose of reducing the fan speed. As I'm sure these delta fans get louder then a 4", you do not want to run these at full throttle. If you run 4 at 50% or less, that is a very viable option for you and can move far more air then a 4" or even 6" inline fan, speed dependent.

praiseodin said:

In a small cabinet that is roughly 3x3x2 = 18 cubic feet would that fan be adequate even tho it would have to pull through a carbon filter.
Say if the filter obstructed it by %50 then the air flow would go from 150cfm to 75cfm, then divide how many cubic feet my box is, which is 18.
That would equal the fan cleaning out the cabinet at 4.1 times a minute.
Unless I'm wrong with my understanding of how it all works :/

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Air movement is a function of RPMs and fan size more or less assuming no resistance. So you can get away with a small motor with little power to deal with a resistance free situation.

It's also why more powerful fans don't necessarily move more air when rated unobstructed.

CFMs here are largely irrelevant if the motor you're using doesn't have any oomph.

CPU fans have no oomph.

I had a relatively powerful axial fan which is built somewhat similarly to a computer fan only a lot more powerful that was fairly quiet (if mounted right) and was acceptable to push air through a small carbon filter (sub 200 cfm).

I love how each person with no experience with these delta fans has a notion to prove that the world is flat. Should we turn this into a does LED lights work or maybe some other about how it only works if 99% of the public agrees.

exabits said:

I love how each person with no experience with these delta fans has a notion to prove that the world is flat. Should we turn this into a does LED lights work or maybe some other about how it only works if 99% of the public agrees.

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Shut up about your stupid fucking loud ass pc fans. They're loud as fuck. Can you not read? Jesus... You are under the retarded idea that having 2 250cfm fans gives you 500 cfm. Tell me how this is possible.

If you honestly think you can take a silly little pc fan and compare it to a 4" inline fan and think the cfm will not drop on the pc fan when you add a carbon filter you are an absolute fool.

Do you even grow? Let's see something. Because all I've seen is you post a picture of your computer. We all have one of those buddy.

praiseodin said:

to be honest, im looking for a decent priced option to pull air through a small filter that ill make and will be quiet as the cabinet may go into either my computer room or garage. both options it needs to be as quiet as possible to reduce suspicion

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http://www.lowes.com/pd_234523-1061-DB204_0__

Don't listen to that moron going on about PC fans. Take it from people who have used them before. They are shit, they are designed to flow the rated cfm with absolutely no resistance. With the resistance from a carbon filter they will move about 0 cfm.

Even the "glorious" delta pc fan. It's still a pc fan, it still uses a micro dc motor that has no torque. If you can stop it from spinning with a stick, it's not worth anything.

Sure, I guess I'll bite. Just because I don't have 3k posts doesn't make me a retard or inexperienced. For the sake of proof I guess I will shit on this guys thread because mrForumwarrior has a beaf with pc fans and me. I suppose your a guy that would say you can't use a window a/c as a water chiller, just as you can't use a fan to do a fans job. Just because it isn't the norm, doesn't make it wrong, apparently many people here could learn a lot from that statement. Here's a few from 2 past grows around 09' and proof I do know what I'm talking about, some would call that intelligent.

Edit: Little ghetto back then...well I've since moved on to bigger and better things, more watts and more pots. Thread Op, believe what you want, I can't fight a whole forum of ill informed neighsayers. I'm sorry to derail your thread because people can't deal with a fan that's different then the norm.

i personally wouldnt risk trying it on my plants lol but if its just noise you're worried about, id recoment using a quality extractor fan with a silencer, keep ducting as short as possible with minimal bends and insulated if affordable, also fileing small v shaped grooves along the entire length of the back edge of the fan blades will DRAMATICALLY reduce noise, hell iv got a 5 an a 6 inch fan running in my bedroom an i sleep soundly lol. i really wouldnt recomend doing what you're doing as air flow is important, you dont want it stagnating in there, if you do try it let us know how it goes! lol good luck

mr2shim said:

Don't listen to that moron going on about PC fans. Take it from people who have used them before. They are shit, they are designed to flow the rated cfm with absolutely no resistance. With the resistance from a carbon filter they will move about 0 cfm.

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not... strictly true.
i have a stealth grow going with a pc 120mm fan pulling through a small yet effective custom built carbon filter. temp in grow room DROPPED, indicating air movement. and when you put ur hand up to the filter you can feel air being drawn. activated carbon layer does not have to be big for 3 or 4 plants, any more then you need real deal I AGREE! providing the air passes over and around the carbon, it stops a big majority of the smell, maybe not as effective as other options, but it does work.
i also have an inlet air duct which has no fan running, i'm not even kidding. the air up in the loft pushes through down into the room anyway (i can always feel the draft) so there is an adequate intake and extraction.

pc fans DO work, even with a small makeshift thin layered carbon filter. i wouldn't go any lower than 120mm fan size tho, that probably would be crap. hell if your not worried about the smell going out, then thats sufficient either way.

fan fire risk, yer.... can agree for most part. but then, the whole part about growing is a fire risk, lol.

if you keep pumping air into a large room with a small fan the large room will hold more air pressure in it then what the small fan did have in the first place ? let the room pressure push air through the filter instead of the fan pressure..

Im engineer and still remember something on my exam on the sizing of idraulic networks...Basically working with the airflow is the same exact thing...The carbon scrubber is simply seen as a resistence in the circuit (and every filter has a different value in base of its constructive properties)...What you really want to look at when choosing a pump or a fan in this case is the PRESSURE DROP that it is able to create...because only this value will be able to tell u how many cfm will be able to pass through the filter...Consider for analogy an electric circuit in which we will have that the CFM (airflow A) that will pass through the resistence (R) of the filter will be given by A=P/R where P si the pressure drop that the fan is able to generate...

So...what does this stuff mean ? We never know the resistence of the filter.. so we cannot solve mathematically the problem...but this just helps us to comprhend which is the true spec that we want to search...It all comes to what airflow we want to pass through the filter...and it is determined by the static pressure that the fan is able to create and just by that...
So coming to the fans...without a doubt inline fans are the best choice but if a pc fan is able to drop enough static pressure i dont really see why it shouldnt do the task...The pressure in general is related to the torque delivered by the fan and it is more or less proportional to the amperes sucked by the motor...On the market there are very diversified fans and some of that (Delta for example) work with much higher courrents (4-5 Ampere) than most of the pc fans available and giving as output high levels of static pressure which are able to push even through a carbon filter...That said it is certainly not the best choice..

depending on size of grow space, the only ones that might come close are going to cost you about the same as typical fan as you may end up needing more than one (but hi-spec PC fans are far less noisy than cheap ruck competitors ect.).

also, the best option in my opinion is to blow through a carbon filter (as fans are most efficient at sucking around the edges), this allows the filter to build up air pressure inside it, and extend it's life by utilizing all of the carbons surface area.
I dont want to get into a suck or blow war lol... this is just my opinion, also based on the general idea that it's best to oversize your ducts, fans and filters.

All this being said, if your space isn't that big and PC fans are your best option, you will definitely be better off blowing through a filter.
Remember, when thinking of PC fans check the pressure rating (can't remember correct term at the mo...), not just the cfm. All PC fans are good at blowing, few are good at sucking... check the brand "Noctua".

Zip

This is an old post, however, one of these:. http://www.amazon.ca/Bgears-b-Blaster-90mm-Bearing-Extreme/dp/B0043GQJ5M will work through a: https://www.rollitup.org/t/the-best-diy-ez-walmart-carbon-filter-for-micro-grows-zen-style.101248/ . Make sure the fan pushes through it as the PC fans aren't designed for pulling. If you wish to test, just tape a plastic garbage page post filter on the exhaust and watch it fill up. Fan on inside of box filter taped to outside.

praiseodin said:

hey guys, ive been having doubts lately about whether a 120mm PC fan is strong enough to pull through a DIY carbon filter. Do you guys use any special kind of fans for that, does it need to be at a certain speed to be able to pull through the filter?
In my cab thats in my signature i was wondering if one PC fan would be enough to extract all the smell from the cab through a filter or if i should make two filters with 2 fans to keep the smell at bay?

Thank you for your help guys! Much appreciated

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Bc northern lights grow boxes uses the same style fans as PC fans but they are a lot beefier, my local hydro store sells them, they look like a normal PC fan but a lot more rugged and I believe they accept 110v. That's what I'm planning on using on a small carbon filter for my micro grow