Incubator fan placement?

Ok I know this a dumb question, but I got a wine cooler nice and cheap. Lucked out. I am going to build a incubator out of it. Does the fan get mounted on teh bottome, middle or top?

Ive seen two videos where theyre mounted on the top but i dont really know to be honest. My thought is usually water bottles are put on the bottom to keep temps stable and hold some heat in the incubator in the event of a power outage. The heating elements are probably better on the bottom since heat rises, making the placement of flexwatt on the top kinda counter ptoductive. So with water bottles and flexwatt on the bottom, theres probably more room for a fan on top.

The purpose of the fan is to circulate the air. If you place it properly, there will be no hot or cool spots in the incubator. Remember, heat rises. That is why many people put the fan up top.

In my incubator I've got one on the top (pointed down on one side) and one on the bottom (opposite side pointing up). This is in a large stand up freezer. The two fans create a circulation throughout the incubator. To test, I have temperature probes on every shelf. It is best to get all of this set up and working (with test egg boxes), before eggs come.

Coolerguys.com has some nice fans and even cords with adjustments for speed. Good luck!

Heat goes up so you want to put your fan on the top to circulate the air back down.