In Jalapeno cold air is pulled from the below intake , pushed upwards and vented through the upper exaust.
Sorry to ask, but are you sure?I've read everywhere that it is not the case.
Even a few posts ago in this topic:
Flash those suckers to 8GH/s and then tell us what the temps are! 
Still trying to get that Atmel AVR Dragon. It's not quite accessible here in singapore... looks like a £1 notebook cooler underneath those bad boys 
i assume its blowing down?
Good eyesight i assume its blowing down?
but it's suppose to blow upwards instead. Didn't switch that on because RPi doesn't have enough power once I plug that in...wont it end up fighting the fans blowing air down? or are you trying to get it to blow the cooler air from underneath upwards?
i have one blowing over my USB ASICs atm