PC Fans for Small Cabinet

d33p

Member
After trying to find something small enough to fit my fridge box I decided to stop being lazy and make something that would work for my needs. Mostly constructed from things I had laying around in the garage. Some old 80mm tsunami pc fans, old rocker switch, some wire, and a 12v power supply from an external sata hd kit. Soldered it all together on a circuit board, used inline 3.5 mm headphone jacks to connect the fans (makes them easy to move around and install.

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These fans are being used instead of an oscillating fan as I have not found any fans that will fit inside my box. These are just for internal air flow, I do have a large blower fan installed in the top of the box with passive intake. (Temps sitting at 75-80)
 

JohnnySocko

Active Member
timely .... but in so far as the transformer thingy goes, what specs/votage/amps does it need to be? numerous inquiries into pc fans and I've yet to fully understand how to hook that thing up, or is it really that broad of a thing in that almost any of those work (or should I cop one specifically for lap tops)?
 

d33p

Member
I used a power pack that was meant to run a SATA hard drive externally. My logic behind this was the fact that pc fans and hard drives run off of the same cabling in a PC. It has 5v and 12v cabelling, I used the 12v to make my fans run at max speed. I bench tested this unit for 3 days and checked it numerous times threw out the day to make sure nothing was heating up. I will be installing them in my box today after work.

For the most part though, every PC fan has a rating on the back and should be ran at those specs or lower. Some are different, but the fan usually tells you Amps and Volts. I used to buy universal power packs that allow you to switch from 3v all the way up to 12v. I prefer these because you can lower the voltage to the fan for speed regulation. I've tinkered a lot with these kinds of things and if you're not comfortable with electricity its not a good idea to create something like this and stick it in a place with water/heat. Home made products like this have a higher failure rate IMO and should be used with caution. If you're looking to do something similar it is a good idea to look up fan modding for PC's. Thats where I started 10+ years ago when mods were less main stream. From there I went on to reading some electronics for newbie's books and a book on soldering techniques. Also bought a couple "bread board" project kits along the way.

Be safe, and good luck!
 

d33p

Member
JohnnySocko, one more thing on the "should i cop one specifically for lap tops". Absolutely not! Laptop power packs are usually way higher volt/amp rating than a pc fan could handle.

This is basically the kit I robbed my power from, and with the right molex adapters...you could literally hook a fan directly to it with no modding. This basically gives you a 4 pin molex power supply.

http://www.newegg.com/Product/Product.aspx?Item=9SIA1ZZ0PG3572
 

polyarcturus

Well-Known Member
they will work fine for internal airflow. albeit if you have enough air swapping in and out of grow chanmber they aren't really needed I have ran rooms and cabs both without internal air movement but the air exchange inside grow area was under 1min when doing that.
 

polyarcturus

Well-Known Member
JohnnySocko, one more thing on the "should i cop one specifically for lap tops". Absolutely not! Laptop power packs are usually way higher volt/amp rating than a pc fan could handle.

This is basically the kit I robbed my power from, and with the right molex adapters...you could literally hook a fan directly to it with no modding. This basically gives you a 4 pin molex power supply.

http://www.newegg.com/Product/Product.aspx?Item=9SIA1ZZ0PG3572
I like using old phone chargers :)
 

d33p

Member
they will work fine for internal airflow. albeit if you have enough air swapping in and out of grow chanmber they aren't really needed I have ran rooms and cabs both without internal air movement but the air exchange inside grow area was under 1min when doing that.
I'm about 1 month in without any fans and my plants could not have thicker stalks. My air exchange is pretty ridiculous. In the multiple times a minute range. I did the math originally and found that I only needed an 80cfm fan for my box, however with carbon filter and passive intake...im using a 4" blower fan at 165cfm. My box pulls air from inside my house and has never gone above 80F or below 70F.
 
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