The ultimate beginner's guide to PC FANS

[ScrubNinja]

Well there are a lot better people to ask when stealth comes into it, but I would still roll with an s&p I think, maybe with pc fan backup/suplementation. I'm unable to find any ratings though for pressure on the s&p. But fair enough, you could do it with pc fans just it'll make more noise.

I take it you'll be making a carbon screen type filter like I bang on about? The best bit is that you can adjust as needed. I'm only guessing here but I think you'd need approx an inch thick or that is what I'd plan around anyway (and allow for more just in case). The strains I've run indoors are not too bad right into early flower. I'm still using kitty litter crystals for the gigantic budding monster in my cupboard. My landlord was 2 metres away from it two weeks into flower.

I had to seperate a hermie I'm making seeds with and it was reaking so I put it in my tent with the bigass Phat filter and a thermaltake smart fan 2 and basically there is zero restriction despite going thru 1.5" carbon. Sadly you can't fit a huge filter by the looks.

My thought is to use something like the fan you chose, but introduce more in line. This introduces more challenges and possible failure but I can't think of many other solutions for cooling at low noise.

Now...."something like" that fan...I say that cos it seems like that fan will be the right volume when you tone it down some, but it's gonna be way underpowered then. There are much better fan choices but they're louder. Basically you've hit the wall that has "stealth and real growing do not go together" crudely grafitti'd on it by some dope growing hoodlum!

330w is a major grow and I'm picturing the sound coming from the stairs as I walk over them and it's a loud noise. My only saving grace with 220w is that I run lights off during the day so I lower my fans to 4.5v and the circulation fans on 12v turn off with the lights. So it really is stealth...during the day. Not at night when the 220w heater is running though.

Another option is to get a really good loud pc fan and simply push into the carbon and hope that muffles all your noise. I think this may be the better option. In short you have a lot of options, but no matter what, 330w (and possibly more for the veg?) is going to take noise to cool. Heat shield makes a lot of sense. Your situation is pretty much the same as Strangely earlier (wussuuuuup bro), so all that advice counts. The more efficient you make things, the less noise needed to cool it. Right now you have made it very hard on your fan so you will need a loud one.

 

[shuggoth]

Has anyone here used the 250mm fans like the ones in an antec 900? Picked up a couple when one of the local computer shops went out of business.

Oh and i had a thought on your scrubber ninja. Could you use stacked 80mm fans with one running backwards? I know it would lose a lot of efficiency but that might make the filter work with the original design.

 

[ScrubNinja]

You mean rotating in the opposite direction but still blowing the same way? Yeah I think you will get better results, but the thing is, it's just too thick. Before I even made it I knew that it would be a poor compromise, so as it stands the compromise is that the layer has to be much thinner than normal filters. We've reduced the surface area considerably, so really there was no way it would ever work without reducing the thickness.

I think the highest performance fan posted in this thread so far has been a counter-rotating fan.

 

[maryjohn]

Heya scrub, I powered up the Delta afb1212ghe. You know, the one with 3.something amps max?

Well, I learned two things: if you hook up a fan to a lab power supply you need a diode on the live side, and it's not a good idea to crank up the voltage to see what your fan can do. I fried one fan, luckily not the power supply.

oh yeah, I also also learned that these fans are insanely powerful. It generated alot of lift.

 

[ScrubNinja]

Why do you need a diode? And are you saying you cranked it over 12v? You are hardcore dude!

 

[maryjohn]

I think I cranked it to 18 while fiddling around. it's good to 13.whatever, but not 18!

less hardcore than bungling.

the diode: it's to prevent damage to the power supply. Diodes are one way streets. i was ok but the guy I bought it from warned me I might blow it unless I add a diode. Not sure but i think the home DIY power supply from a PSU already has a diode?

 

[ScrubNinja]

I dunno but I hope mine has one, lol. I've never heard anything about this - I hope someone can elaborate.

18...haha, I wish you had youtubed it. All for science!

 

[maryjohn]

it was smokin'....

 

[oldone]

Hey Scrub-

I take it you'll be making a carbon screen type filter like I bang on about?

Absolutely, thats what the brown framed triangular thingy is. I thought 150 sq in was quite big. What is huge?

How do you get a 1.5" thick filter with zero restriction? The delta fan has 11.4 mmH2O pressure which is a bit more than your thermaltake. Do you think 2 of them (side by side or stacked) would work?

BTW, I will be using 220 watts for flowering and 55 or 110 for veg. My cab is 40"w x 32"h (48" to the "peak").

Thanks,
OO

 

[ScrubNinja]

Oldone - right, I totally missed that. So I see you vent out to the right, but where does that go? Imagine if you removed the white section and put the screen right across that whole area, so your filter has the area of almost your whole veg cab and flower cab combined. Or even leave it there and have the screen go around it for nearly as much space. Either way there's a lot of ways you can increase the surface area more than that impossible to adjust triangle. An important note is that carbon tends to settle no matter how much you shake it. So you would stand the risk of an air gap forming at the top of the triangle. Risk of air gap with a horizontal screen - none to zero.

I've said it before - area is the number one issue, and that is what lets me pull thru 1.5" on the Phat filter.

I know, it's huge But it really saved my ass and I was quite happy to pay the money for it. Activated carbon is so hard for me to find, and expensive where I have found it, that I think it works out cheaper for me to buy a real filter, and drain the carbon out, than to buy carbon in packets. So messed up. But anyway.

Inner diameter is 150mm (6") and length is (I think) 500mm (20"ish). Now, the 6" diameter gives us a circumference of 18.8". So the total area equals *tap tap tap* ....*resists urge to post the count*....376 sq inches.

So we can safely say that 376 sq inches of 1.5" thick carbon poses little to zero obstacle for the thermaltake sf2.

I know with my box of 220w, the only way I'd be able to call it stealth was if I did a dedicated vented hood. As well as that, you're in a good position to vent each cab seperately. You don't really need to rely on one fan for any particular reason in yours. How about a fan on the flower cab exhaust, and a fan on the roof of the veg cab, both blowing into that small room. Then you could also add one somewhere else if needed.

Hope that helps mate, I probably skipped something but it's late here and I'm very high, just ask again if anything confuses.

 

[maryjohn]

this entire screen gets covered in carbon. I came up with this design when making the super simple stacker. Did you get it from my thread scrub?

 

[ScrubNinja]

No I came up with it myself some time ago. I know that Red had done a similar thing with his rubbermaid but at the time I couldn't understand exactly how he'd achieved it. I think he used a container that fits into another container or something. So I decided to just use a screen to get the absolute maximum screen area. Strangely though, I picked up a screen thing exactly like what you have there in a 2nd hand shop. Whatever they are they make good carbon filters I suspect

 

[maryjohn]

I guess great minds think alike!

either that or it's just the principle of increasing surface area without adding too much effort.

 

[ScrubNinja]

Both, I like to think I can say that I've recommended it to quite a few cab builders and no complaints yet. One guy mentioned he wasn't totally happy but without being rude, you do have to pay a lot of attention, depending how you run things. In the model above I didn't glue the flyscreen down, and I think there were some fine gaps there, but for the most part it worked well. I mean, if you make it so there's no gaps, explain how it would not work, ya know.

So anyone doing that design should strive for no gaps whatsoever. And yours is a good way around that problem completely, maryjohn. It's a solid unit, and I totally recommend something like that. Theres no chance for gaps, and no chance for settling issues, and easy to obtain surface area. It really is the perfect carbon filter. Man, you know those pipe expanders used in all the real DIY fliters? Every f*cking store sells these dumbass lopsided off centre ones that I can't make a damn filter with!

Another issue people should remember to pay attention to, and this would apply to you too MJ, is a pre filter. With that westaflex fan in the photo (hard to make out - stealth ) I had enough negative pressure that I could simply place a sheet of aquarium foam over the tip of the ducting leading to the filter, and it would suck to it. Crude as hell but I got my damn buds. Thing is, it was operating for a long time without a pre filter and there was a noticeable drop in flow over that time.

Filtering your intakes will help, but I suspect my coco drying out and blowing around is the main problem. I have no pre filter in my current cab but hey, I haven't even put the carbon in and it's halfway through flower. I was very skeptical about kitty litter crystals when Hydro-Soil recommended them. I read a lot on them and most people said no they don't work. But some big grows, and even one really, really big grow were being filtered with it.

I tried it and I wasn't impressed at all upon testing it with incense in the cab. It basically did close to nothing but I figured it was good enough for veg. Here I am, halfway through flower though. I even have the activated carbon sitting there but there's just no call for it. The whole house gets stanked out the second I open the door. I think I'm very close to it giving out though. I was really surprised. It's free-er flowing than carbon and thus you have to use more of it. There are a few other things to look out for too.

 

[maryjohn]

Prefilter: I use quilt batting right on top of the screen. Once in a while, you do have to clean any filter, ya know.

 

[maryjohn]

While I'm at it, did I mention it doesn't have to be sealed? It just need to be easier for air to flow through the carbon than around it.

 

[ScrubNinja]

Definitely - that's why I came to the conclusion it was near pointless to have it on top of the screen. You have to remove the carbon to get to the prefilter.

I bought a roll of that quilt stuff. I think it's the same - mine is called frost mat. I just got it for, yup, prefilter material. Aquarium foam is so expensive.

 

[ScrubNinja]

While I'm at it, did I mention it doesn't have to be sealed? It just need to be easier for air to flow through the carbon than around it.

That pretty much implies sealing it, bro. Which is the easier path for the air to take? A gap? Or an inch or so of granulated carbon?

 

[maryjohn]

Well good point.

Ok, may I point out that I didn't seal last rime and got zero smell? Maybe it was the weight of the carbon ? I did notice it sagged. Maybe it self sealed?

 

[ScrubNinja]

Do you have a photo of the old setup to refresh my memory? I thought you used a plastic container which was pretty well sealed. You mean it was unsealed where it sat on the other container? Cos that would make perfect sense. You were pulling thru the carbon if I remember right, so you were creating a negative pressure environment. Air couldn't blow out if it wanted to. Just like my big filter in the tent there. There is the filter, then a fan sealed airtight to the top of it, but the ducting is basically just resting on the fan. I put a tab of tape to help it keep the angle, but it's not sealed. Because that is a positive pressure environment inside the ducting, it can only leak clean filtered air back into the grow, not smelly unfiltered air into my exhaust duct.

Filters are all about the pressure. You can dick around sealing things when you are working against pressure, but it's an uphill battle. Far better to let the pressure do the work for you. And if I'm right about your original setup mj, that's a perfect example.