Hot air rises; cold air falls. This is the reason why chimney smoke
You can achieve the same "stack" effect with a much less expensive
Cooler Master CM 690, or the more expensive HAF-932:http://www.newegg.com/Product/Product.aspx?Item=N82E16811119137http://www.newegg.com/Product/Product.aspx?Item=N82E16811119160&Tpk=N82E16811119160
We've built PCs with both cases, and they are superb:
both top and bottom panels have fan grills, and
both allow the PSU to be mounted at the bottom rear.
The HAF-932 also supports 2 x PSUs.