Posts Tagged ‘Data Center’

Fire Triangle

Sunday, September 13th, 2009

195px-Fire_triangle.svg

Data Center facilities, unlike our homes and office buildings, requires a different treatment in terms of protection against fire.

But before we touch on that topic, lets first understand the nature of fire. To do so, lets learn about the fire triangle or combustion triangle. This is the basic foundation for understanding the ingredients necessary for most fires. It has largely been replaced in the industry by the fire tetrahedron, which add further aspects.

The triangle illustrates the rule that in order to ignite and burn, a fire requires three elements: heat, fuel, and an oxidizing agent (usually oxygen) and the fire can be suppressed or extinguished by removing any one of them. Only in the right mixture or combination, will a fire occur.

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Limits of raised floors in Data Centers

Sunday, September 13th, 2009

I have recently written about the relationship of CFM and cooling.

Most of the arguments in the industry about using slab floor instead of raised floor are effectively cooling higher density payloads beyond 4kW/rack. And that is a very low payload in today’s context.

Sun_SCAThe picture on the left is an example of a data center on slab floor (this is Sun’s Santa Clara data center). The theory behind cooling such a facility is to bring the cooling closer to the heat source and deliver it horizontally (row-based) or vertically (rack-based), instead of distributing over the sub-floor.

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PUE (part 1)

Saturday, September 5th, 2009

There is a saying “what you can’t measure, you can’t manage”.

When it comes to the data center facility, the Green Grid recommended using PUE (Power Usage Effectiveness) as a metric to measure data center efficiency. PUE is quite widely adopted in the industry today. It was intended (and still is) to be a simple metric for data centers that is easy to understand and use, that enables DC operators and IT administrators to quickly estimate the energy efficiency of their data centers, compare the results against other data centers, and determine if any energy efficiency improvements can be made or if there are potential problems. The PUE metric – which is the ratio of a facility’s total power to the power being drawn by IT equipment – requires complete knowledge and understanding of each component in the data center and its power consumption.

However, if you would analyze the ratio carefully, you realize a catch. “Power being drawn by IT equipment” – this is a variable number. IT equipment’s power consumption varies from time to time, depending on their utilization. For example, a server with 10% utilization will consume less power than a server utilized at 90% level.

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CFM and Density in Data Centers

Wednesday, September 2nd, 2009

I recently received a query regarding the relationship between CFM (cubic feet per minute) and density of heat load that can be supported in a data center using a room-oriented cooling architecture.

CFM is a non-SI unit of measurement of the flow of a gas or liquid that indicates how much volume in cubic feet pass by a stationary point in one minute. rate of air-flow. In a typical data center facility that has conditioned air being delivered through a subfloor and via perforated tiles to cool down IT equipment in racks, it sure helps to understand the relationship between CFM (air-flow), temperature rise, heat dissipation and the amount of cooling capacity required. The diagram below charts the relationship between the required cooling capacity (in kW) per tile versus the required air-flow (in CFM), assuming a delta temperature of 20′F.   (more…)