Since I've found an adequate cooling scheme, see:
http://forum.kiwisdr.com/discussion/1939/alternate-cooling-method#latestI have gone on to finalize my "kiwi cluster", 4ea BBAI based units combined with a common fan.
I went this route to reduce fan noise. The box on the back is a plenum for a single 90 X 90 mm AC fan. I used a best quality ball bearing fan.
Initially (see other thread) I had some ducting in the inlet side of the kiwi enclosure. I found today that was no longer needed, I stay below 44C, only 19 deg above room ambient.
Some of you may say "wow, that's a lot of dollars"... I can duplicate that for $1400 or $25/channel (there's the potential for 56 channels there). Better performance and less money that dongles!!