How to Turn a PC Fan into an Exhaust or Intake Fan?

MacLeven

Member
how much are the fans at radioshack
I Don't Know About Radio Shack But I Went to My Local Computer shop, And The 6 inch Fan Was a $1.75 CAD So It's Really Cheap. Cord Is Prolly More Expensive, But Chances are you have one laying around in a Box Somewhere, I Know I Have like 30 of Em... Who Knows?
 

blackcap

Member
How would I go about powering a CPU fan that has end connectors like this? I have two of them from old Gateway CPU's I had laying around.

 

monty Python

Active Member
Hi there. Excellent thread. Im just about to harvest my first plant and plan on making a dry box and extract the air into my tent and let my main filter get rid of the smell.
Only problem is, iv run out of plug spaces, its only a 4-way one. But rather than buy a bigger plug adapter and powering the pc fan with a 12v adapter is there any way i can run it off a battery ? I havent a clue about electrics, voltages n stuff like that just mindfucks me.
I understand eventually the battery will run out but its not like im using this for a full grow, its just for like 7 - 12 days or so il need it running for.

In short, is it possilble and SAFE to run a pc fan with a battery ?

Thank you.
 

Mr.Natural

Active Member
Hi there. Excellent thread. Im just about to harvest my first plant and plan on making a dry box and extract the air into my tent and let my main filter get rid of the smell.
Only problem is, iv run out of plug spaces, its only a 4-way one. But rather than buy a bigger plug adapter and powering the pc fan with a 12v adapter is there any way i can run it off a battery ? I havent a clue about electrics, voltages n stuff like that just mindfucks me.
I understand eventually the battery will run out but its not like im using this for a full grow, its just for like 7 - 12 days or so il need it running for.

In short, is it possilble and SAFE to run a pc fan with a battery ?

Thank you.
Monty If you have'nt already, go ahead it won't hurt a thing ...safe as can be ....

:peace::peace::peace:
 

Jakenbake

Active Member
There don't seem to be a lot of specifics in this thread and I've noticed a lot of people asking questions that could all be answered quickly. This is a great thread, but I feel a few more details would help tremendously.

When you have a PC fan it should say on it the volts it is designed to run at and the amps that it pulls while running at full speed. If you have a 12vdc fan that pulls .38Amps you need a DC power adapter that can push the same or more amperage. On the power adapter it will say the current output. I have a 12vdc power adapter with an 800ma current output, and because both of my fans pull only .38A (or 380ma) each, it powers them both just fine. If you are pulling more amps than the power adapter is rated for, it will eventually burn out which can be a fire hazard. If you have 3 times as many amps as you need, that's fine. The fans only pull what they need, you cannot over power them unless you're using a higher voltage.

Which leads me to my next topic. Two things can happen when you run a fan at a different voltage than it's designed for. If you run it at a higher voltage, like the power supply, it will eventually burn out. If you run it at a lower voltage it puts strain on the motor and will lessen the life of the fan.

Batteries naturally output a DC current, so you can power anything that requires DC current off a battery, as long as the battery can handle the load.

Hope that helps some people =)
 

Crazygrowguy99

Active Member
These fans are exceptionally loud, someone walks into my house and the first thing they say is "What is making all that noise!" Anyone know of a quiet fan?
 

machnak

Well-Known Member
So could I use 2 120MM fans for my MH/HPS light? Or would it not be enough? The fans will be used as intake and exhaust for the room itself as well.

Also is 120MM the best fit for a 4 in whole? 120mm=4.74in but has anyone used or done something similar?
 

blower

Active Member
What about a fan that is cheap to make or buy, but to exhaust from a bigger like-tent? Help!
 

Rankdank

Member
To acquire these just call your local p.c. repair store, I bought 2 ball bearing fans for 5 bucks a piece. Grant they aren't new, but they work great and you can't hear them. They obviously work great in P.C. grow boxes. Just my 2 cents.
 

Rankdank

Member
I need some assistance to from this thread. I've tried several times, following the directions of this site, and had no success. I've read the entire thread to make sure I didn't miss anything and now I'm just frustrated. I've got a fan 80mm pc fan with the red/black/yellow wires (understand I don't need yellow) that has a a .2a (200ma) output. Now the adapter is a AC adapter with a input of 120VAC, 60hz 6w/ output is 12VAC .33a. I have a very limited experience of electronic mechanics.
 

Jakenbake

Active Member
I need some assistance to from this thread. I've tried several times, following the directions of this site, and had no success. I've read the entire thread to make sure I didn't miss anything and now I'm just frustrated. I've got a fan 80mm pc fan with the red/black/yellow wires (understand I don't need yellow) that has a a .2a (200ma) output. Now the adapter is a AC adapter with a input of 120VAC, 60hz 6w/ output is 12VAC .33a. I have a very limited experience of electronic mechanics.
I believe 80mm fans run on 5vDC, not 12vDC. Check on your fans label what it says. It should say right next to where it say 200ma. Also make sure you're attaching the positive lead from the fan to the positive wire coming from the adapter. Once you figure out the correct voltage, try running it and if it doesn't work try switching the wires.

Your adapter may also be burnt out in which case you're not going to be getting anything out of it :P
 

Jakenbake

Active Member
Trying to run D.C. on A.C.? Not usually a good thing.
Guess when I looked closer RankDank, you did type output = 12VAC. If it says VAC it's outputting AC current and not DC current which is what you need. Your adapter should say output = 12VDC.
 

RastaMonsta

Active Member
hey im in the process of wiring some fans. i have 2 80mm 12v fans 2.16 watts 2.24 air pressure mmh20, i found this adapter,will it work for 2 fans? i blew up four fans already before doing research.i want to make sure im not going to blow more up.help needed plzzzzz
 
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