The ultimate beginner's guide to PC FANS

[ScrubNinja]

I noticed the Delta didn't seem to spinning at full rpms, wonder if that was related.

Definitely! I overloaded without thinking the other day when I added a fan. It seems to me like the highest amperage fan is affected the most in a situation like that.

What's the best way to really bump up the air pressure?

Better fans like mj suggests although see the following diagram, mj, as inline is better for pressure.



Stacking directly is a bad idea with pc fans, so you need a gap between. A problem arises in that I'm not a physics professor, so I can't say how much of a gap, but as noted, a blank fan spacer seems to do a pretty good job. Me personally, I'd keep it further, or either side of the filter, like mine.

An intake fan is another way you could have them inline, but that creates it's own issues. I was actually reading today about an old mine shaft grow in canada, for the government's medicinal supply. Down in the mine shaft, way below surface, the pressure is much increased. They also used only intake fans to push the supply in, rather than drag it out. A high pressure environment, and the plants grew much faster than some in a control growroom on surface level.

So when I finally hack open my fridge to grow in that, the sealable environment would be perfect for an intake fan only setup.

Zettl's lucrative marijuana contract comes from a series of happy coincidences. In 1991, after hard rock miners noticed orange and apple seeds, which they'd spit out, growing as high as six inches in total darkness before they died

Truth is, they can't even say for sure, but it's worth an experiment imo

 

[disfunktional]

i am eagerly awaiting that build. it oughta be one bad ass fridge

 

[OBK]

I didn't realize the Delta's got that beefy. Twin 3 amps..koolaid man say Ohhh Yeaaaah! How many dbs are those at max? I'm looking at the pfb1212uhu-f00, 4amp, over 250cfm and 36mmh20...

 

[maryjohn]

Turned all the way up they are very loud.

 

[kiheibuilt]

scrubninja, huge mahalo for this thread, it's been extremely helpful for me since I'm a noob. I'm in the planning phase and am trying to learn everything I can about quietly moving the air so thanks a bunch.

 

[ScrubNinja]

Disfunk, don't hold your breath bro, I need my fridge more than a new grow box, lol. Very slow project that one, I basically have to wait for the fridge to die!

MJ & OBK, The thing I don't like about the real high cfm deltas is they all seem to have the directional fins for the 250 cfm'ish models. Well the ones that I looked at anyway.

Kihei, my pleasure bro, if you get stuck just sing out

Well guys I spent a while doing this so I'll show you. For anyone that remembers my old rushed setup with a blue LED thermaltake pulling through the internal filter like this:



I finally got that shit sorted! Check it...

There is a 92mm Delta (1.35 amps on sticker - FFB0912EHE) blowing into the carbon filter and boy does it blow The heat is now extracted from the top of the tent, and even with my shitty old ducting, no smell leaks can occur. The only positive pressure is inside the carbon filter where you want it. There's a PC PSU and fan speed control on the shelf above the filter. I tied heavy wire around the filter as extra support (not in photo).

Then it got taped in but I forgot to get a pic of that : The ducting fits over comfortably and being oversized, there's little resistance. It's been sitting .4 to .5 degrees above ambient. It just sucks that ambient is so high. I also forgot to make a pre filter so I have to pull it apart

My carbon filter in the cupboard was giving out slightly today because of the humidity I think!

Here is a database of fans. Might be useful although there's no pressure figures.

Smoke weed everyday!

 

[disfunktional]

saweet set up with the fan/filter!!

 

[ScrubNinja]

Thanks man, I finally finished it, lol (the pre filter). Feels good to do something you've put off for a long time!

I forget if I mentioned that thermaltake hanging in front of the filter. Because the exhaust flow is so diffused, the fan blows the collected hot air out into the ambient air flow that slowly passes through the other side of the room. Works great.

If you've ever wondered if it's better to push or pull, see this... pretty convincing argument to push. I certainly have no complaints pushing. Peace.

 

[kiheibuilt]

I'm trying to get an idea of how many dBs would be too loud for stealth use. I noticed that the Delta fan can move air but at 55 dB, is it noticeable?
My future micro-cab will be in my bedroom just 4' from the bed, so I gotta go as quiet as possible but still have enough pressure to push through a scrubber. What would be the highest dB I could get away with to stay stealthy but still push through a scrubber?

 

[ScrubNinja]

Hey Kihei, Do you want it so someone can stand right in front of it and not hear a thing? I would probably look at something <20db as your final volume depending on a few details like cab wall material, ambient noise etc. If you wanted to undervolt a delta, I would probably start with a delta thats around <40db. I have no idea really, that's just a best guess from the one I undervolted.

55 dB, is it noticeable?

It's very noticeable It's not just noticeable, it's irritating. But volted down they become much quieter. I just listened to mine on 5v and it's about as loud as an older cheaper VHS player, playing a tape. It's a soft, low whirr. Not silent, but quite stealthy. For that amount of noise, it's blowing way more than if I just used a quiet fan on 12v though. It rocks.



Edit: This is the fan in question, the Delta FFB0812EHE 80x38mm. (you can hear it on the link) Mine is 1.35 amps though.

 

[maryjohn]

Mine is about as loud as a computer at 5v. I have the crazy deltas.

Perception of sound depends on setting too. If you keep the light off something for instance, people "hear" it less. If you already have ambient noise, nobody hears anything. Hell, a hammacher-schlemmer white noise generator would make it next to imposiible to perceive.

 

[OBK]

Wow nice job on the scrubber, scrub...liking the cardboard reducer (tried to make one out of duct tape but the cardboard would be much more solid).

Any idea about how many cfm's the delta is pushing undervolted?

Also I'm shopping for a new fan controller (thanks again for the heads-up on the sentry lx)...do you think 15w per channel should suffice? I assume when I do the watt-to-amp conversion, I can assume 6v from the speed controller....

 

[kiheibuilt]

Hey Kihei, Do you want it so someone can stand right in front of it and not hear a thing? I would probably look at something <20db as your final volume depending on a few details like cab wall material, ambient noise etc. If you wanted to undervolt a delta, I would probably start with a delta thats around <40db. I have no idea really, that's just a best guess from the one I undervolted.



It's very noticeable It's not just noticeable, it's irritating. But volted down they become much quieter. I just listened to mine on 5v and it's about as loud as an older cheaper VHS player, playing a tape. It's a soft, low whirr. Not silent, but quite stealthy. For that amount of noise, it's blowing way more than if I just used a quiet fan on 12v though. It rocks.



Edit: This is the fan in question, the Delta FFB0812EHE 80x38mm. (you can hear it on the link) Mine is 1.35 amps though.

Thanks for the reply. I guess I'm trying to target the right #'s since I'm looking at fans around the 20-25dB range. Those Delta fans do look good, I like the way you've got the fan attached to the scrubber. Nice work.

 

[LEDGro]

Hey all. Im glad I found this thread. I am planning a small rubbermaid grow. Its about 9 Cubic Feet and I was planning on using a S&P TD-100x running at 1/4 speed or about 25 CFM.

I will be blowing though a carbon scrubber of some sort to handle the odor. I want it to be stealth as possible but will probably put my servers in the same room to add to the white noise and make any other fan noise seem like it should be there.

Which setup would be more silent?
Can the PC fans push through a carbon filter?


I like the setup that scrubninja uses with a small rubbermaid full of carbon and a cpu fan at the bottom. How do you keep the carbon out of the fan?

 

[ScrubNinja]

Cheers all.

OBK. Every fan controller has it's own quirks so always check a review or two. The one I use allows you to slow down a fan as slow as it will go before it stops spinning, and to turn it right off. Others will keep spinning at a set minimum, some won't hit full speed and so forth. They may even mention the voltages in the review. Thermaltake even make a remote fan speed control.

Hard to put a figure on the cfm as I've seen me be way out many times The little blower fans I posted a while back are only 20cfm, yet they feel like far more, they can be felt across the room, like they were 60, 80 or something, so it's just too decieving to guess. I think it blows like 80 on 12v, which would make it less than 40 if we converted directly, but no way is >40cfm fan from a foot away, with a foot of bulb before it, ever cooling the base on the pll in question. Even with a normal "decent" sort of flow you'd have with CFLs, the base would blister skin and melt plastic. It's the hottest fluoro light I've ever felt. So in my opinion it's blowing way more than the direct amperage translation, if you catch my drift. The base is (almost) cool as a cucumber now, the lamp shade's plastic clip clips on right below that base part. The base is cooler than the 11w CFLs with good flow across em.

For your fan controller, watts/volts = amps. So 15 watts = 1.25 amps. I'm quite fond of my Vantec Nexus NXP-301. Cheap, handles 0 - 12v, 18 watts per channel (1.5 amps) and handles 3 channels. I love mine although the included CCFL setup is crap and shouldn't be used.

LEDgro, I've not used the S&Ps, hopefully someone who has can chime in. I'd simply compare the specs. Because you're comparing ac and dc items, compare watts instead of amps. I suspect the s&p would win out but I don't know the specs.

I keep the fan on when I fill the filter, there is too much air blowing for anything to fall in.

 

[OBK]

Hey scrubninja, thanks for the pics and post. I'm looking at other controllers now. There's a lamptron that's 6X45w...should be able to handle those 2 and 3amper delta monsters, even at full bore, no? It uses something called pwm... does that require a pwm fan? I'm having trouble finding decent controllers that can do 30+ watts a channel...There's the Zalman ZM-MFC3, but it ain't cheap...

And while we're on the subject, what is the downside to the directional fins on the bigger fans you mentioned before? Do they make flow too diffuse? I wanted to use something big and nasty to pull from a filter and exhaust, and those suckers have the mmh2o mojo!

Speaking of...how do you like the phat filter compared to the carbon bed filter you made? Sorry for all the questions at once , I'm pretty excited because today, with much help from especially this thread (and vent101), we have temps that vary from ambient by one deg (before it was 12 deg F over amb). Part of it was opening another intake, but also it's the AFB1212HHE (@ a stealthy 6v) doing its thing, replacing and sending an anemic silenX to light circulation duty.

 

[ScrubNinja]

Hey bro good on ya. Yeah I'm never happy until I get 1 or 2º over ambient - ambient here is often already over the max as it is

I suspect you were looking at the Lamptron FC2. For a bit cheaper (where I'm looking anyway) is the Lamptron FAN-ATIC 5-Port Military Switch Baybus which does an incredible 60w/channel!!! The 45w is equal to 3.75amps so yeah, it's plenty for that. I've only looked at a small range of controllers available to me really. But don't rule out a dedicated power supply, like the adjustable I use in the cupboard. 3 amps and keeps it simple.

The directional fins create turbulance, they break the flow, ya know? Air by itself doesn't make any noise as far as I'm aware, but when it has something to disturb the flow, it makes noise. So basically the specs for those fans will tend to be a bit louder. There's absolutely nothing wrong with 'em if they're within your db range. Also, they make less of a noise difference as the fan is slowed.

I love the phattie!!! It's a little hard to compare to the old setup or to my cupboard because it's blowing diffused out of a tube, so the only thing I can really feel with my hand is the (extreme!) suction where the exhaust duct enters the top of the tent. I can't feel that bit on my cupboard because of the design. So it's a bit of a guess but overall it seems to be kicking ass. Certainly, temps are like .5 to 1º f above ambient usually, with about 100w of lights.

At lights on I've always been running the Delta at max speed (noisy even inside the filter) but I realised now I can have it on stealth levels and the temp is fine. Overall I prefer the carbon screen method because it's adjustable, whereas the phat filter is set at 1.5" carbon depth. I think the surface area is approx the same. If you can find a filter with similar dimensions as the phat, only with 1" carbon depth instead, you would be laughin'. It all comes down to personal preference really, it's easier and not much more expensive for me to buy a Phat and if you follow the rules, you know it's gonna work, even for the dankiest tomb weed.

Yeah folks, overall I would say avoid silenx fans - those figures aren't achievable.

And now I have a question for you guys Is it bad to blow a fan on t8 fluoro bulbs? I set this up like so...there are no fans on the canopy or bulbs, just this extraction one which blows air straight up, past the fan adapters, then into the exhaust duct. I have reason to believe they don't put out max light unless they're a bit hot around the bulb?

 

[OBK]

Dunno about the T8s...I blow a thermaltake on my T5s with no problem.

I admit I'm a bit lost with Lamptron Military Switch Baybus...isn't that just a badass on/off switch? Yeah I was looking at the FC2, but it looks like there may be issues with it and Delta fans.

http://www.overclock3d.net/reviews.php?/cases_cooling/lamptron_fc-2_rheobus_fan_controller/

Edit: From what I can tell pwm fans and controllers are optimized towards full-throttle performance, and don't work great for the stealth (pwm-version of undervolting?).

 

[ScrubNinja]

Actually it's t-5's you gotta watch for with the fans... I got the answer:

The ideal temperature for a T8 lamp is 25 °C (77 °F) while the T5 lamp is ideally at 35 °C (95 °F) [via wikipedia]... meaning that you should probably blow some air on your tubes, because if tour cab is at 80-85 then your bulbs are way higher, and certainly above 77f

"According to a data sheet from Sylvania, a T8 bulb operates at 100%
efficiency between 22 and 27 C. At 30 C, efficiency drops to 97%, at
35 C to 91 %, and at 40 C to 85%."

That's very interesting about the controller. Mine does the varying speed thing a little but it's no big deal although it could be annoying to a stealther. There's no squeal at least. It's a good reason to go with an adjustable high amp supply, there's less points or chance of failure.

I forgot to answer you about PWM. I don't know much about it so I just avoid it. PWM fans are not so common and so there's not a good selection, plus I've heard of bad times trying to get it all working with various speed controllers etc.

Crap, you're right about the Military Switch Baybus : I don't read the fine print, sorry. Who on earth would pay that much money for that? I'll keep my eye open for heavy duty controllers that are suitable.

 

[maryjohn]

Hey scrub, I came home today, and my delta's were not running. Cab had been on for 3 hours, and the temps were in the 90's. The culprit: I had set them to 4.5 V to keep the cab a bit warmer. That's enough to run them, but not enough to start them.

so I was wrong before.