The ultimate beginner's guide to PC FANS

[ScrubNinja]

Nah, sounds logical to me

Okay, so the FFB0812EHE (air circulation in tent) is running on a 5v 1 amp phone charger on a timer. These are it's specs:

80x80x38
.9 amps (1.35 on sticker)
5700 rpm
80.16 CFM
20.63 mmh2o
52.5 dba

Even though it has a slightly lower decibel rating than the 92mm above, it's noticeably louder because of the 80mm high pitched whine tone @ 12v. It purrs quietly at 5v and those directional fins make it perfect for cooling long lengths like the t8 or pl-l bulbs.

 

[615]

That's sweeeet, think I'll put my Ultra Kaze in at 4,9V and see if I even need a 6-7V adapter for it.
At 9V it's a f-in hurricane though.

btw, the 120mm Ultra Kaze just feels alot different from the 80mm casefans, it's reallly heavy and sturdy.
Can't wait for lights on and start messing around with it.

 

[ScrubNinja]

Hey well one thing to keep in mind is that it wouldn't be hard to find an adjustable wall wart for a reasonable price for the Kaze. It's nice to be able to adjust so easily, like if you have a surprise visitor or something like that. Or just for seasonal variations in ambient temps.

My thermaltakes start up and run fine on 4.5v so 4.9v for the Kaze could work. The main thing is to make sure it will start reliably from a dead stop at these low voltages. Even if it's not on a timer, you still need to ensure it will start up in case there's a power cut.

 

[615]

Yeah, I've got a ThermalTake speedthingy but it's ~70miles away at a friends house so it'll take some time for me to get it.

4.9 turned out to be just enough to keep it breezy in there. 9V created such underpressure that ripped my insulation and then started flying it around in the case.
I seriously need some massive intakes. Off to buy a few sewage elbows tomorrow if I don't find any in the basement.

 

[mad librettist]

remember, at lower voltages, the amps required goes down.

I can show you the readout from my power supply.

 

[J23]

Hi Scrub,
Is it possible to use a thermaltake speed controller for the other fan? I'm thinking about hooking it to delta pfb0912dhe (delta used for pushing through a Can Filter 705).

thanks much!
J23

 

[ScrubNinja]

Howdy! Hmmm I would guess not really. In the past I've hooked them up in some weird ways I can't even remember but it didn't work properly. I had it on a weak 80mm sunon I think, and instead of being a speed dial, it was more of a switch - off at low dial, but twist it a little and bam, it's on full speed. I wouldn't do it again because I realise now it's a fire risk

Gut feeling says it would work if the amps were similar to the thermaltake but a Delta would melt it to bits, heh.

 

[J23]

Hi Scrub,
Thanks for a fast reply. Can you suggest some other way to control the speed of a delta fan (anything different from undervolting) ? I'd like to control it to adjust the air flow through my scrubber. Thnx again, Scrub.

 

[ScrubNinja]

Crikey, they use that fan to cool Harley Davidsons!

3.1 amps is a lot. I can't think of anything offhand except for what's been mentioned (and I forget how high those went). Was it you I was talking to about the heavy duty speed dials? Are they not suitable? They were mentioned some pages back, I think BC Chronic is or was using one too and it's just a dial, no housing etc. Can't recall the name, sorry! Otherwise people including me seem pretty happy with the high amp adjustable voltage supplies.

Another tactic is to use a PC's PSU to supply a whole range of voltages. Find the suitable voltage, then get a suitable adaptor at that voltage. I know you said no undervolting but hey, it works. Hope it helps.

 

[BTLSfan]

Hey Scrub Im very interested in the fan you have pushing through your Carbon Filter...I recently bought a filter of that size (approx) from HTGS..You may have mentioned it before but what model delta fan are you using to push through that..

I recently bought a Delta AFC0912DE whicg us 2.5 amps and pressure rating is something like 25......think thats too much? Im cooling about 260 watts CFL in an 18 x 18 x 36 box

 

[ScrubNinja]

Hi BTLS,

the one hooked up to the carbon filter and doing all the exhausting is a 92mm FFB0912EHE and it's running on a 5.7v 800mA phone charger 24/7.

The fan says 1.35A on the sticker.

* 92x92x38mm
* 1 Amp
* 110 CFM
* 16.90 mmh2o
* 55 dB

Keep in mind I don't have any formulas I use, I go on gut feeling. Gut feeling says your fan will work good though. Apparently yours has a speed control, so, great.

 

[smokeymacpot]

nice guide.

it is possible to get 7v from a pc psu as well as 12 and 5. instead of going red to black or yellow to black, try red to yellow it gives 7v cant remember which one ends up as negative, but you'll figure it out as a pc fan will only spin one way.

 

[ScrubNinja]

Cheers Smokey! There's a "map" of the PSU voltages on the first post, can also get 10v (+5, -5)

 

[smokeymacpot]

Cheers Smokey! There's a "map" of the PSU voltages on the first post, can also get 10v (+5, -5)

i did see that, but you can get 7v from the molex connector. no mods needed, nor do you need to go near the 20pin connector or inside the psu.

 

[ScrubNinja]

Ah, cool, I get ya. For the ultra lazy, you can also buy molex adaptors pre-wired to do it.

Edit: found a great article for anyone interested: [FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][SIZE=+1]Keeping the Fans Quiet - Power Control Methods[/SIZE][/FONT]

 

[tryptaphyte]

Gratitude scrubninja! Your input on this thread is most appreciated. Reputation coming your way.

Had an idea for a grow cab, by integrating a shell of a pc in the cabinet you could give indication to noise to potential hazards while also neatly mounting one of these nice LCD fan controllers in there that have thermometers, allowing fans to be adjusted according to cooling requirements. Would look the business IMO

Going to draw some plans up in CAD in the next few weeks, hopefully post to scale in pdf.

Set on some deltas, btw how did you get on with those thermaltake XB pro blower fans ? Read most of this thread but has to skip to the end.

 

[ScrubNinja]

Thanks tryp! I never really used the XB fans in anything. I had one in my CCFL pod, but had heat problems - even with my 92mm delta, I still had problems - so that cab just had inherent problems, lol. My overall thoughts are that for micro/stealth use, an axial is best. Blowers will create the most pressure overall via design, but they do make a lot of noise doing it, and don't blow all that much air versus the noise they produce. The high end axials have no probs making pressure, cfm, and at lower noise too. (in my opinion). The XBs only have like 20cfm so that's worth noting.

If you look at the design of axial vs blower, the axial is just more efficient at blowing air because it's simple.

I look forward to seeing what you come up with, and yup, there's a lot of possibilities with all the PC mod equipment around

 

[Nick Mack]

Thanks for all the info ScrubNinja, I thought I knew it all when it comes to PC fans but how wrong was I?!

I will be setting up a new microgrow in a week or two and I'm just trying to decide the best route to take vent wise, I already own a Can 2600 and was hoping to use that rather than DIY a mini filter.

Here are the specs of the filter;

Specifications

Max Recirculating (Scrubbing) CFM: 90 cfm / 142 m³h

Max Exhaust CFM: 42 cfm / 71 m³h
@ 0.1 sec contact time
Prefilter: Yes
Mounting: Bayonet or Regular
Flange: 4"

Dimensions: (with pre-filter)
·Outside Diameter: 14cm / 5.5"
·Height: 45.3cm / 18"
·Total Weight: 4.5kg / 9lbs.
·Carbon Weight: 2.1kg / 4.63lbs
Pressure drop at max cfm: 42pa / .20"wg

Recommended Fans:

FAN Watts Consumed Filtered Air CFM

Can-Fan 4" 62 Watts 88 CFM
6" Axial (Computer Fan) N/A 79 CFM

4" Axial (Computer Fan) N/A 39 CFM


I have seen a Delta fan for sale (these don't seem easy to come by in the UK), the FFB1212EHE. Here's the datasheet;

http://www.delta.com.tw/product/cp/dcfans/download/pdf/FFB/FFB120x120x381mm.pdf

Does this sound like a good fan for the filter if used at 5v? I understand I will not truely know until I've given it a go, but does this seem a good combination in your experience?

I will be using the fan in a DR40 tent (1.3x1.3x3.9 foot) cooling a 150w HPS, the ambient room temps are around 50 F so I don't need much in the way of cooling just need enough brute force to pull through the filter.


Cheers.

 

[tryptaphyte]

Sorry another question, there has been an emphasis on static pressure; however, is it wise to sacrifice airflow for pressure? I have noticed with smaller fans, pressure is increased substantially but CFM is sacrificed, haven't passed ventilation 101 yet, should really get cracking at that.

To drive a carbon scrubber is airflow needed as much as pressure?

 

[ScrubNinja]

Tryp, it's a system, like all of growing. No one spec is the be-all and end-all. They all work together. CFM without Pressure is useless. Pressure without CFM is useless. It's like how I can't just buy PLLs and assume my grow will be awesome - I have to provide all things - medium, food, ventilation, and so on.

Every setup is different so I can't really answer if it's wise to sacrifice this or that. In this thread at least, the emphasis has been put on Pressure because nobody was really understanding the need to have both CFM and Pressure, before that.

Nick, welcome to ic. Thanks for adding so much of the details. I think you linked to the wrong data sheet though, so I followed these specs. As usual I am just "gut feeling" it, but I'd say that fan is spot on perfect.