What I was referring to was the fan specs showing the fan was a 24v fan that moved a LOT of air. That's what did not make sense so I cross referenced the part number and found another data sheet that show the same part # and 2 different set of specs:
http://www.cooltron.com/uploads/Cross%20list%20-%20Cooltron%20vs%20Orion.pdfFD6025B12W11-81 ★ 40.20 CFM 6,600 RPM 47.00 dBA
FD6025B12W11-81 8.80 CFM 1,800 RPM 19.10 dBA
The only difference I found was the one marked with a "★" had Auto Restart Protection (not sure exactly what that means).
So one is an anemic low RPM fan that does not move a lot of air and the other is a high RPM fan that is much noisier but moves more air. I have no idea why they use the same part # for 2 different fans.
I am not sure which one is used in the Koobs Sky kit but I am sure someone here on the forum has one that can share the actual part #'s.
BTW - you can buy 1-2 engineering samples of almost any manufactured product. I am sure I can get a couple of these fans with 1 phone call to the manufacturer.
MikeV