I usually orientate that fan depending on the direction of the heatsink fan. If the fan is blowing ontop of the sink, I'd use that case fan as intake. If the sink fan is exhausting, I would use it as ...

With a week of high temperatures in the 90s and plenty of summer yet to come, it's time to turn on the ceiling fans. If you have a ceiling fan, changing the direction of the blades is a great way to ...

on the outside edge of the fan you should see 2 arrows...one of them points horizontally, along the circumfrence of the fan, and the other is vertically to the fan....that one indicates the fans ...