About 8 months ago we were faced with an expansion issue where our datacenter upgrade was delayed due to permits. At the time sun had just announced their blackbox, now called the S20. During the road trip I got to walk through one of these. I found the cooling aspect to be very interesting. It works on front to back cooling but has what I would call radiators are sandwiched between each set of racks. From my non-technical point of view on HVAC this seemed to reduce a large amount of wasted cooling seen in large room datacenters. Is this something we might see in future fixed datacenters or is this limited to the portable data center due to technical limitations ? Due to cost we didn't get to use one but I found the idea very interesting. Derrick