The Hot Aisle reader, Mark Hatton of Trapdoor dropped me a mail a few days ago about a company based in Las Vegas called Switch Communications and the CEO, Rob Roy was making a lot of claims about how good their proposed new data center was. You can read the original article in The Register.  Some of the stuff is plainly marketing hype but there are some quite neat design approaches that are worth a second look.

In the next couple of months, Switch will open a new facility located just a few miles from the McCarran International Airport called the SuperNAP. Roy describes the 407,000 square foot facility as the most energy efficient, tightly packed data center on the planet.

The claim to be “the most energy efficient” is patently not true as the facility does use refrigeration for equipment cooling (hard to avoid this when you locate your data center in the desert). Data Centers like BT’s 21st Century Data Center use 100% Fresh Air cooling and have a significantly better PUE.

Switch has spent years banging away on a data center design that runs contrary to conventional thinking. Most large scale data centers utilize raised floors where cold air is pumped through holes in the floor and picked up by servers and storage systems. This type of architecture often results in the top parts of the computing systems getting very hot. So, companies have developed all manners of weird contraptions ranging from liquid cooling systems, heat socks and even data center robots that seek out warm spots to try and avoid concentrations of warm air.

I absolutely buy this. Raised floors are plain stupid. Hot air rises, cold air falls so why deliver cold air from below where it is essential to maintain a high plenum pressure. It is a well known fact that equipment located towards the top of a rack runs hotter than equipment at the bottom of a rack. Why engineer around the problem when you can engineer the problem out?

By contrast, Switch has created its own system called a T-SCIF (Thermal Separate Compartment in a Facility), which lets Switch abandon expensive raised floors altogether.

You basically back a server or storage system into the T-SCIF container and create a seal that separates the cool air pulled in by the front of the system from the hot air exhaled from the rear of the system. Unlike most data centers, Switch does not need to deal with intermingling cool and warm air. The hardware receives only cool air, while the hot air travels out through ducts above the T-SCIF. This design lets Switch run servers at full power and allows it to stack as many systems as possible into a given space whereas many data centers must avoid filling up racks with hardware because of heat and power concerns.

So Switch uses Hot Aisle containment with no raised floor. Hot air is exhausted from the facility directly as (even in the desert) air temperature in the shade is cooler than exhaust air. Switch use Fresh Air or Free Air cooling in the desert. At night the fresh air is actually quite cold dramatically reducing the input energy required to run the facility. What is not stated is how Switch manages humidity in their new facility as desert air is likely to be very dry and after refrigeration likely to have a relative humidity approaching zero!

We can do 500 or 600 per cent more cooling per cubic feet per minute than everyone else who designs their data centers with raised floors and cooling systems from Liebert,” Switch CEO Rob Roy told us. “The raised floor kind of works against the laws of physics. Cold air does not want to fly up through a room. Everyone in the world knows that is probably not the right way to approach things.”

There is some truth in this statement spoilt by the 500 or 600 per cent exaggeration.