How to connect cooling fans

[Needeles]

Hello, I am just wondering how to hook up some cooling fans for my tank. I have a couple of 90mm CPU fans I can use but they have the 3pin connectors. I don't mind if I have to cut the connectors off but I am not sure what I have to connect then to for power. I have a pile of old power adapters but not sure if I need a certain type. Most of them were for normal electronics such as cd players, phones, cell phones, routers, ect. Could I just use anyone or deos it need to be a specfic type? How would I then wire it up to work. DO I need to splice into the adapters wires then connect the fan wire or do I need something else. Please let me know as my tank keeps climbing in temp and because I don't have an AC unit I can't cool it that way. The fish I am really worried about are my swordtails and my cories as they both like it cooler then what I am at. Currently my tank is sitting at about 84d F and continues to climb. Thanks

[Jericho]

You need to know how many volts the fans are, are they ac or dc? If they are 110 ac then they will need to be wired to a plug and put into a wall socket. If they are DC (which they probably are) you will need to find a power supply that has the right voltage and enough amps to run the fan. Then you will end up cutting the ends off of both the fan and powersupply and doing the wire work.

[mvigor]

I found this bit online:


Q - What is a 3-wire fan?
A – The third wire in a 3-wire fan measures the rpms of the fan. It is sometimes referred to as a tachometer wire. Our 3-wire case fans are referred to as sensor fans.
So you can run your fan with just two of those three.

I'm fairly sure that most of these fans run on 12 volts, so find an adapter among your bunch that is at least 9 volts, if not 12 and pick the biggest clunkiest one as it's likely the one capable of pushing the most amperage rating through.

Then, as Jericho says, cut the ends off of both the fan and the power supply and fiddle around until you find the right combination of two wires that will run the fan. Solder it together or just tape it up well and you're done.

[Needeles]

Hello and thanks for the reply. If I do connect the wires and they are the wrong combo will anything happen or will it simply not work? Will it fry the fans or will just readjusting the wires simply work? Also will I be able to run 2 fans off one power adapter or do I need to have seperate adapters for each fan. My plan is to modify my hood and fit the fans in somewhere. I just have a standard Top Fin 24" Flouresent Hood. Thanks

[mvigor]

I really don't think you'll fry a fan by trying the wrong wiring. If anything it will run in the wrong direction, but probably nothing worse.

If your power supply is rated for enough amps (or milli-amps mA), it can drive two fans in parallel. If not, you'll have to use two separate supplies. Do you have a computer's power supply lying around? That would run dozens of fans I suppose.

Oh, BTW, I was born July 23rd as well. We're like, calendar brothers. LOL...

[DeputyChiefJR]

it'll just run in the wrong direction....My grandpa and I used to play with simple DC current stuff like that and would get a random chuckle off wrong guesses..

[Needeles]

Ok I did some digging and found the 2 biggest adapters I could find. Below are what they say on the backside of them. Let me know which one would probably work better and if they might be able to power 2 90mm CPU fans. Also they used to go with a couple RCA Cable Modems. Thanks

Adapter 1
Sino-American
Model A30980
AC Adapter
Class 2 Transformer
Input:120VAC 60Hz 15W
Output:9VDC 800mA

Adapter 2
Sino-American
Model A41209
AC Adapter
Class 2 Transformer
Input:120VAC 60Hz 20W
Output:11VDC 800mA

[Jericho]

Here are the specs on that fan.... Use the 11vdc power supply and you should be able to run both fans... The starting voltage is 7dvc and the 11 is close to the normal 12vdc operating voltage...


P/N
A2013
Fan Speed
2500±10% RPM

Fan Color
White
Max. Air Flow
52.24CFM

Fan Dimension
90x90x25mm
Max. Air Pressure
2.84mmH2O

Rated Voltage
12V
Noise
21 dBA

Started Voltage
7V
Bearing Type
1 Ball 1 Sleeve

Rated Current
0.18A
Life Expectation
60,000 hrs

Power Input
2.16W
Connector
3 Pin

Weight
103 g(0.23lb)

[Jericho]

Also if the wire colors are red, black, and white the most likely color code is
red=positive
black=ground
white=sensor

[Needeles]

Hello and thanks for the help. I have gotten the fans setup. My next question is what would be the best way to set them up. I have them currently sitting in the front of the tank with the front lip of the hood open and they are blowing twords the back of the tank. They are sitting at a slight angle. I don't have a big opening in the back but there is some room there. Is this the best way to run them and if not what would be the best way? Thanks again.

[Jericho]

The best way to ventilate an area is you put the fans at the larger opening, but you need the wind from the fans to blow over the entire opening. That will pressurize the tank and the air will flow out the smaller hole with force.

[wackydan]

They are 12volt, but you can usually run them pretty low. I'm running a 120mm case fan at about 6 volts. You just need to make sure that it starts turning everytime. Lower voltage means less air movement, but less noise. It will probably move enough air to do the job though.

[sirgardens]

The above is a great idea.
Do they sell cooling fans specificly for aquariums?
I have 125 gal tank I need to cool down similar situation.
What size or how many fans would I need.
I dont have a canopy but dont have a problem building one if it will help with the cooling of the tank.
Thanks alot....

[Needeles]

Hello, I beleive that they do sell pre-made fan systems but will most likely cost more thn just simply doing it yourself. Do a search on google for "Aquarium Cooling Fans" and you will find many different places that can sell you something to suit yur needs.

[sirgardens]

Thanks Needeles.Im thinking of doing it my self but dont know were to begin.

[Needeles]

The easiest way and cheapest is to do it yourself. It is pretty easy to do also. Simply get an old pc fan and get an AC adapter that is rated for 12v. Next simply splice the wires on the fan and the adapter then connect the wires together. Most PC fans have 3 wires, you will only need to use 2 of them. It will either work or not work. If the wires are backwards then it simply won't run. Once you find the right wire combo then tape the wires with some electrical tape and plug the fan in. You will then have the adapter that goes right to the fan and it will start to spin. Then just set it in an area on the tank so the fan blows over the water. I have 2 fans hooked to a 12v adapter and it runs both fine.

[sirgardens]

Thanks again Needeles.It almost sounds too easy.

[hmt321]

I just finnished a project like this yesterday and i think it cost me a total of $60.00 US, I used 4 fans, two 3" fans blowing into the top, and two 4" fans blowing out of the top. I am hoping that the bigger fans will create low pressure inside the hood and in effect move more air.
The fans were about $8.00 each and i bought a 12v power supply from radio shack for $20.00 or so. Just make sure that the power supply has enough amps to push your fans. i will post a pict later today.

most comp fans have 3 wires, red, black, and yellow. The yellow is the sensor wire and you probably do not need it.

this was a very simple project.

this was for my 125 gal tank

[Needeles]

WOW almost $60, you could have went and bought a pre-made system for that. The reason I did it this way was the fact that it was so low cost for me. If I would have spent that much I would have just bought one that was already setup for the job. I guess that is just my thought. I hope it works good for ya. It does a great job for me when it isn't above 90d F.

[hmt321]

the hood itself was much more than $60.00 but it is exactly what i want. see this post for the hood

http://www.aquariacentral.com/forums/showthread.php?t=78526

[jaymasta]

We have a few local used computer stores, and I was at one the other day and they had a huge box of old working supplies, including MANY computer fans of various shapes and sizes ranging from $2.00-$5.00, and old computer power supplies starting at $5.00 you guys that are interested might want to check out some used computer stores, I think I could build a decent fan cooling system using 2 fans for less then $15.00, and all the stuff comes with a 90day warranty....

[Star_Rider]

the new 120's are quieter and move more air..some are even adjustable..hmm

I may use on of those I pikced up 2 120 adj for $20