Fans for cooling..

Firsttimer

Active Member
Does anyone have any suggestions on where to find quiet cooling fans for my grow closet. My light is a cool tube so most of the heat is pulled out with the fan attached to that, but I still need a vent fan. I know the computer fans are quiet, cheap, but I don't think you can just plug them into an outlet. Any suggestions???
 

mogie

Well-Known Member
How to turn a PC fan into an exhaust or intake fan?

Contributed by: Flowerman
Images archived: 2001

Just for fun, I wanted to show how easy it is to turn a PC fan into an intake, or into an exhaust fan. The fan I am using is quite small, but the objective is still the same. The first step is to find or buy a 12v DC plug adapter. This fan here is rated at 80cfm, which will work for a small box set-up.

Here's is some info on the 12v DC adapter: (Model 420A4141)

Output (DC) 12.0V @ 500mA
Output Voltage VDC(1)
Input 108VAC
Output Volts @ 100% Load 10.20
Input 132VAC
Output Volts @ 100% Load 13.60
Input 132VAC
Output Volts @ 10% Load 17.40
UL(2) UL*
CSA(3) L
Plug(4) 1



Simply cut the wires at the end, and strip down about a ¼ inch of bare wire is showing.

If you don’t know which wire to wire up, for instance they’re all black wires, don’t worry, it will only work one way, and if wired wrong, will simply not work at all. But the idea is, black to black, red to red. This one here that I used, had one black and one red coming from the fan, and from the adapter, one black and one black and white. The black and white wire from the adapter got wired to the all black wire from the fan. And the all black wire from the adapter, gets wired to the all red wire from the fan.

To add another fan, just connect the wires of the same together. All black goes with black, all red goes with red. So you would still only use 2 connectors all together. Here’s a few more pictures. But for the most part, I just wanted to show how simple it is. Make sure you get an adapter which is rated DC for the output.



Finished


Testing


Also a worthwhile consideration is places like radio shack and grainger also have nice 4" muffin fans that move as much as 200 cfm and more, which run on 110 vac. They come with a handy power cord that has a special connector on one end for the fan and a plug on the other end for plugging into the wall socket or humistat / thermostat.​
 

bleorg

Active Member
I've got two 12v dc computer fans from radioshack. I had them hooked up to a 12v 1000ma adapter. They were too powerful for my growbox and you could hear them running all over the house. So I cut the wires on a 7volt 800ma adapter that came with a phone answering machine I no longer use. I hooked the fans up to that and they're now a perfect strength for my small cabinet and are much quieter. It's only 60F in my house, I'm using a 125w cfl in a small cabinet about 3 feet high X 30 in wide X 18 inches deep, it stays around 75-80 in there with the light and fans on. I tried the same thing with a 5volt adapter. The fans were completely silent, but not quite strong enough. With the full 12 volts, the fans kept it down to room temp, which is too cold right now.

I just ordered some 6" clip on desk fans from compusa's website. They were pretty inexpensive. It's hard to find fans in any stores this time of year, at least in cold areas like it should be here now(it feels like April right now though).
 

mogie

Well-Known Member
If you are trying to make use of a PC case fan, but finding it gets quite loud, this is for you!

You will need the following:

o Insulation foam strip (any thin foam should do)
o Heat-shrink tubing (from any electronics shop)

Step 1 - Preparing your mounting screws



Take your heat-shrink tubing and cut 4 pieces - each around the width of your fan mounting (Picture 2). Insert the screw into the tubing and shrink to fit (Picture 3).

You now have rubber coated screws to dampen some of the vibrations.

Step 2 - Mounting the fan

Take your foam tape, peel off the backing and place along the edge of your fan (the side facing the wall). Make SURE that all sides are covered!

As you can see, overlapping the tape is fine.

Screw the fan to your box wall tightly! The foam will compress leaving an air-tight seal around the edge of the fan.




The rubber screws coupled with the foam seal will stop vibrations from the fan, leaving only the sound of air passing through it. This can be reduced to silence by running the fan at 9 volts!








Contributed by: aallonharja

A much simpler approach is using one of those camping mats made of polyurethane. Cut a strip of the mat that’s long enough to run 3 times around the outer sides of the fan.

Make an opening for the fan that is slightly smaller than the fan with the mat, OR depending on your setting, make an frame for the mat/fan combo that you can fit on the inlet/outlet hole (out of wood or whatever).

Stuff/slip/slide carefully the fan - mat combo into the opening - simultaneously insulating any light and air leaks AND very effectively sound dampening the fan. It’s also possible to run wires through between the mat layers as it flexes to accommodate wiring.

Usually its possible just to make the opening and slip in the fan-mat combo, no screws etc needed. If the strip of mat extends in front and back of the fan, the sound of the fan (blades) and air rushing is also dampened.
 
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