That's my tv stand (rather, a picture of it that I found on the internet. Those cubbies in back are half open to allow easy access from the back of the unit. (You can kinda see the light pouring through in that picture) Basically, on the back of each cubby, on the bottom half of the back is a backing piece of wood--the top half of the back of the cubby is completely open. We use our ps3 (sitting on one of those cubbies) to stream most of what we watch. I've got plenty of 120mm pc case fans I could hook up in the back of the unit, but I don't know a good way to do so.
I'd like to just have it be on if whatever is in that cubby is on. I suppose I could get an arduino and hook a thermometer up to it and say if it gets so hot turn the fans on--but that seems kinda expensive since there are three cubbies and I'd want it individually controlled for each one. I've also never looked into using one of those fans outside of a mobo, but I'm sure I can find some dohicky somewhere to interface it with some other device.
That's just what I've got handy (minus spare arduinos). If there's some other way to accomplish this I'd love to hear it.
Also, sorry if this isn't the proper place for this question, it seemed like the most appropriate place on the forums judging by the title of this individual forum.
edit: in case it's not obvious, by cubby I mean the opening above the drawers. Google "hemnes tv stand" (from ikea) in case that picture isn't clear enough.