On my previous setup I used a regular household fan that I aimed at the surface of my sump - worked well enough. With my new sump though, I could not easily place a typical household fan anywhere and get decent cooling. I decided to take a different route.
I bought 4 cheap computer cooling fans - the 120mm variety. These run on 12V DC and they come in a wide variety from near silent to high CFM models. I chose the highest CFM model I could find, and the bonus was they were only $6 each. I figure with the salt spray they will collect I will be lucky to get a year out of them, but at $6 each, they represent a cheap investment. I zip tied the four fans together through their mounting holes and this provides a surprisingly rigid unit when complete.
IMG_4201.JPG
Next I took some left over acrylic and welded it together as a support frame that sits nicely in the top "tray" of my sump.
IMG_4203.JPG
In order to power these, I went out and got one of these ebay:
12v.JPG
It comes with a molex end that connects up with typical computer fans. Here I did run into an issue. The molex connector has 4 pins. 12v on one end, the two middle pins are ground and the pin on the other end is 5v. The adapter I got only had 1 ground pin on pin 2 (pin 3 was not connected). The fans I bought had molex connectors, but they only had ground wired up to pin 3. This isn't a problem in a PC, but with my adapter I was out of luck. On top of that, I didn't really want to stack 4 molex connectors together and have this plugged into the end of the adapter anyway. My thinking was these are probably not well suited for a salty environment. The solution was to chop off the molex on the adapter and on the fans. I soldered the grounds together and the 12v wires together and covered these connections with two layers of heat shrink tubing.
Another note on PC fans. You may find that the fans come with 3 wires. The third wire is for variable control - motherboards on PCs can typically slow down the fans based on thermal requirements. In my case, I'm plugging the adapter into my EB8 and a simple on/off program is all I'm after. The PWM control wire from my fans is capped off.
Here's the final product:
IMG_4197.JPG
As a bonus, they light up with blue LEDs which goes well with the aquatic theme.
Bookmarks