I am putting a pc fan on my incubator at this very moment! You will need a 12V adapter that plugs into the wall. We found one from one of my boys silly toys. And then wire the fan and mount it. Radio Shack Fan is the kind I have.
I bought a still air, styrofoam LG incubator years back and added an old fan from a PC. As mudfarm said, you'll probably need a 12Vdc adapter (aka wall wart). Check the fan, it should have the power requirement written on the label. From what I'm hearing, most of the incubators with air circulation only turn on the fan when the heater goes on. Mine stays on all the time as this provides more uniform temp. Plus, I didn't have to concern myself with connections to the heat controller.
This is the direction I'm going, a pc fan with 12 v adapter. The fan that is going to go into our incubator is from the pc dump. Why buy new when you can recycle. I'd like to know where you are going to mount this fan. I am wondering how and the where.... Good luck to you!!!
As long as the fan doesn't blow directly on the eggs, it doesn't really matter where you out the fan at. In the homemade bators most people put them on the side. Just be careful, if the fan is too big it can make your temp go up. You might want to think about using a 9v adapter instead. And most incubators that have fans that I know of, the fan stays on all the time.
