Case fan positioning

All right… well… I have a case that has a spot for a 120 mm fan on the front, back, and side of the case, with the side one on the opposite side of the motherboard. And I was kinda hoping someone here could help me out on figuring out which direction the side fan should be facing. I know that the front fan should draw air into the case, and the rear one should push it out. But what about the side one? Currently, the side fan is the only one I have (fixing that in about a week), and it WAS pushing air out, which is how it was set up when I got the case, and also how most people seem to think it should go. However, when I turned it around to draw air into the case, everything dropped ten degrees Celsius. Speedfan even tells me that the overall system temperature is cooler than normal. Now… is this like a long-term loss kind of thing? Or should I turn it around to push air out when I get the other two fans? Does the direction of the side fan not really matter, as long as there are two other fans? Or can the most efficient use of the side fan change with the case?

Edit: Also worth noting that, after being turned around, the fan not only looks cooler (it has LEDs in the frame of the fan), but it is also keeping the processor at 50 degrees Celsius, now that my CPU fan just died =)

Every side fan I’ve seen draws air in.

Mine draws air in.

Hm? All right, sweet… that’s how I thought it should be, but other people kept telling me otherwise, and the fan came pushing air out. It seems logical that the front and side would pull air in, but the multiple answers were just confusing me.
…it seems weird that so many people would have theirs pushing air out, then <_<

I don’t have a side fan, but the side vent is drawing air in. Since it’s for the processor fan.

In the front and side then out the back =3