Wow....that's going to be a good one. I've seen something similar and I think I know the kind you're talking about. The only one I am familiar with is the one that fits in the rear slot on the back of the computer. I think it was called a "turbo vent" or turbo fan". It has a slim design but I don't know how big or small the fan and casing is. I saw those on Ebay and at Office Max. I might be off track but I hope I helped than hurt.