Raised Flooring Obsolete or Not?

mstansberry writes "In part three of a series on the price of power in the data center, experts debate the merits of raised flooring. It's been around for years, but the original raised floors weren't designed to handle the air flow people are trying to get out them today. Some say it isn't practical to expect air to make several ninety-degree turns and actually get to where it's supposed to go. Is cooling with raised floors the most efficient option?"

Comments

Turns?

[mboverload]

As long as the space under the floor has a negative or positive atmosphere I can't see how somme turns have anything to do with the air flow.

Re:Turns?

[swb]

I still miss why running cabling under the floor is worse than running it in overhead trays. Either the trays are too high to get at without a ladder (thus making them at least as inconvenient as floor tiles), or they're too low and you bash things into them.

Overhead tray systems also suffer from a fairly rigid room layout, and I have yet to see a data center being used the way it was originally layed out after a few years. Raised flooring allows for a lot of flexibility for power runs, cabling runs and so on without having to install an overhead tray grid.

Raised flooring also offers some slight protection against water leaks. We had our last raised floor system installed with all the power and data runs enclosed in liquidtight conduit due to the tenant's unfortunate run-ins with the buildings drain system and plumbing in the past.

I guess overhead tray makes sense if all you want to do is fill 10,000 sq ft with rack cabinets, but it's not really that flexible or even attractive, IMHO.

I wouldn't say they're going to become obsolete.

[wcrowe]

Another big reason for raised floors is to handle wiring. I know companies where it was installed only for this reason. Cooling wasn't even on their minds.

One way to fight this -- the CHIP

[Work Account]

To paraphrase a popular saying: "It's the COMPUTERS, stupid!"

Inefficient architectures must be discarded to make way for more modern, smaller, COOLER processors.

Let's address the real problem here -- not the SYMPTOM of hot air.

We need to address the COMPUTERS.

Re:One way to fight this -- the CHIP

[n0dalus]

Perhaps more importantly, better software solutions can make large hardware systems unnecessary. Instead of running and cooling 10 servers for a certain purpose, write better software to allow you to do the same thing on just one or two servers. If you cut down the amount of servers in the room by enough, you don't even need dedicated cooling.

Why do devices need to be cooled?

[WesG]

I am waiting for the day where someone invents a computer that doesn't need to be cooled or generate excess heat.

Think about the lightbulb....A standard 60-watt incadescent bulb generate lots of heat. A better design is something like the LED bulbs that generate the same amount of lumens, with much less power, and more importantly little to no heat.

Good design can allow these devices to not generate excess heat, hence eliminating the need for the raised floor.

It's the physics, stoopid

[zooblethorpe]

Note that I'm not calling the parent poster stoopid, but rather the design of forcing cold air through the *floor*. As the parent here notes, cold air falls. This is presumably why most home fridges have the freezer on top.

I was most surprised to read this article. I've never worked in a data center, but I have worked in semiconductor production cleanrooms, and given the photos I've seen of data centers with the grated flooring, I guess I always assumed the ventilation was handled the same way as in a cleanroom -- new air in from the ceiling, old air whisked away through the floor. (This ensures that any particles, which will naturally fall if heavier than air, will be sucked out of the room.) Note that this is obviously *not* a passive system designed to use convection, but rather an active system using lots of fans.

While a passive convection system with the cold pulled up from below is a nice theory, you can run into the same problems others have pointed out -- what if the bottom units suck in all the cold air? The top units are left too warm.

Meanwhile, if you drop cold air from above, sure, the top units might suck a lot of that in -- but any cold air that isn't sucked in will naturally continue to drop relative to warmer air, ensuring that the lower units are not cooked. If you want to be especially careful about it, you could route all the cold air outputs towards the perimeter of the room and put the uptakes in the center of the ceiling to ensure a vortical flow.

Just my ¥2.