I just posted this to Reddit, but I want to share with you guys what I just started working on.
My face gets super toasty within about 10 mins of wearing the Rift. There's not much airflow. Thanks to Oculus uploading those cad files for the facial interface I put this together.
Tested it with a 12v blower fan that I had on hand and it works great.
Next step is to order a 5v 35mm square fan, find a better solution to get power (need 5v or 12v), and gets some foam for the interface.https://www.reddit.com/r/oculus/comments/57chcl/cooling_venting_fan_for_facial_interface/
So it's clear, this is the direction of airflow