12v Computer fan question

mwz

Member

Veteran

• Jan 9, 2013

• #1

Hi!

I have a couple of 12v computer fans that originally were going to be used in a computer project. I'm now considering using them as apart of my future indoor grow build.

My questions are:
1) Are 12v computer fans worth using?
2) If so, what's the most energy efficient way to get them working and running off 220v house power supply.

An easy way would be to get an old computer power supply and run them off that. My only concern is that computer power supplies often have much higher wattage than what's needed to run the fans. Running a 400w power supply for 4 x 12v fans would be the energy equivalent of running an extra 400w light! I was struggling to find a low wattage computer power supply on eBay.

Anyway, any input is much appreciated.

 

ozman

Member

• Jan 9, 2013

• #2

Well I dont know about running them off of 220 volts,but if you get a 110 adapter to 12v they work great.I use them in my cabinet with an adapter,they havent given me any grief or problems.I use mine for exhaust vent and they work like a charm.The bbig thing is to make sure they will move enough air to suit your needs.

 

G

gyntwaiser

New member

• Jan 9, 2013

• #3

I used 120mm fans sum yers ago.
I had sum old modem/xmas light power adapters.
Most power adapters work if they r 12v output, so chek ur closets n attic n c if u find any, before buying computer power supply from ebay.

I quess if you have alot of em in use, its wise to use computer power suppply.

 

mwz

Member

Veteran

• Jan 13, 2013

• #4

Thanks for the replies guys! I'll follow these ideas up

 

rives

Inveterate Tinkerer

Mentor

ICMag Donor

Veteran

• Jan 13, 2013

• #5

A computer power supply isn't going to pull the rated wattage unless you have that much equipment hooked up to it. That wattage is the maximum that it can put out, not what it will draw with minimal loading. There are undoubtedly more efficient options because of the power supply fan, the fact that it puts out a number of different voltages that you wouldn't be using, it being optimized for heavier loading, etc, but I doubt that it would add more than a few watts beyond what your fan would pull.

 

GP73LPC

Strain Collector/Seed Junkie/Landrace Accumulator/

Veteran

• Jan 13, 2013

• #6

i too have used 12V DC fans in a cabinet with much success... a 110V AC adapter to 12V DC is what you need...

check out the link in my sig for pics of the cabinet i am talking about...

VERY STEALTH FISHTANK !!! FTW !!!!

 

V

Vokuhila

New member

• Jan 13, 2013

• #7

I'd suggest using a 9V power supply, that helps to keep the noise down.
A power supply from a PC might work, but to reach their peak efficiency they need to be operated near their maximum capacity and some require a load on the 3.3/5V rails to start up.

 

coloradcannabis

Member

• Jan 15, 2013

• #8

i splice one into a 12v adapter, like a old phone charger. Works like a baby charm.

 

foomar

Luddite

ICMag Donor

Veteran

• Jan 15, 2013

• #9

Old phone chargers work very well , a good way of recycling older ones in the 6 - 12 volt range that dont fit modern lower voltage phones , run slower but quieter at below 12 volts.

Have an ancient fan from a server thats been ventilateing a veg box 24/7 for twenty years this way without incident.

 

messn'n'gommin'

ember

Veteran

• Jan 15, 2013

• #10

This link goes a long way to explaining it:

"The ultimate beginner’s guide to PC FANS," by ScrubNinja
https://www.icmag.com/ic/showthread.php?t=131842

Good luck!

 

mwz

Member

Veteran

• Jan 19, 2013

• #11

Thanks so much everyone!! So much information, this is fantastic! I'm leaning towards the old phone charger route, I have a few spare

 

N

nukklehead

Active member

• Jan 19, 2013

• #12

I have 2 120volts that I bought years ago off radio shack web site.. they are still truckin along. take em out 2 x a year and clean em.
I splice into regular 14 gauge extension cords and straight into the outlet. Dont know if they make em any more you can try google em if you want. Just trying to save you a step of using a transformer but hey an old charger is a good idea if you cant find these anymore.
I may have to use that approach if not made anymore.

 

foomar

Luddite

ICMag Donor

Veteran

• Jan 19, 2013

• #13

Have in excess of thirty old and current power supplies for phones , laptops and music devices from 3 to 40 volts around the house , dreadfull waste and difficult to recycle.

Have used what i can in various projects , converting bulhead lights to led,s and suchlike , kept a few out of landfill.

Fitting a single large fan of this type in place of six cheap and nasty chinese crappy ones in a led array silenced it effectively and brought temps down.


My fan is actually a lot older , stripped it from an ex MOD fileserver in 1980 and it was ancient then but of solid build quality designed to be lubricated and rebrushed , pre Intel and microsoft and before it was cheaper to replace than repair or service..

So its actually ran 24/7 for nearly forty years , 23 on this 9 v phone charger , doubt a modern fan will last as long esp the chinese crap i see in led arrays , quality ones intended for PC,s should fare better.

 

M

mamachachas

New member

• Jul 18, 2017

• #14

Switch Power Supply vs AC/DV Adapter

Switch Power Supply vs AC/DV Adapter

Probably a dumb question, but I'm having a bit of a hard time finding AC/DC power adapters at my local retailers. I came across a couple Switch Power supplies that are 100-240V AC 0.4a Input and 12V 0.7a Output. I did a little research on them, but I'm wondering if these are suitable to use for connecting my computer fan to an outlet. I realize it's a lot higher amps than I need, but I have a 12V .24a fan that I'd really like to use for exhaust- and the basic 5V 0.5a usb adapter is just too slow operating under 5V. I notice immediately that the Switch Power supply is copper wires, so I'm a bit hesitant to try it. Thanks in advance!

 

OldPhart

Member

• Jul 18, 2017

• #15

mamachachas said:

Probably a dumb question, but I'm having a bit of a hard time finding AC/DC power adapters at my local retailers. I came across a couple Switch Power supplies that are 100-240V AC 0.4a Input and 12V 0.7a Output. I did a little research on them, but I'm wondering if these are suitable to use for connecting my computer fan to an outlet. I realize it's a lot higher amps than I need, but I have a 12V .24a fan that I'd really like to use for exhaust- and the basic 5V 0.5a usb adapter is just too slow operating under 5V. I notice immediately that the Switch Power supply is copper wires, so I'm a bit hesitant to try it. Thanks in advance!

Click to expand...

Switching mode power supplies are the way to go, in fact *most* power supplies are switching mode any more, even if they say it or not. The major advantage of the switch mode supplies is the fact that they handle short circuits and overloads quite gracefully; they just shut down, and often times will restore operation when the fault is cleared. There are a few of the switching supplies that may require cycling the power to them after a fault to restore operation.
Try overloading a standard DC supply, and it will often do one of the following, either burn out, blow a fuse, or over heat. The way to tell the difference is to feel the weight, the switch mode will be much lighter because it doesn't have the heavy transformer in them.