As technology advances, we are not only able to deploy more powerful, energy efficient devices into the whitespace, but also to monitor and better understand the IT load and its resulting environment. Monitoring is a valuable tool to data center operators, allowing them to better understand and control aspects of the whitespace (power, assets, inlet temperatures, etc).  But is this enough?

Accurate modeling and simulation is the most practical way to predict the effects of any changes made in the whitespace before they are deployed.  However, using an accurate model to simulate IT deployments is crucial. As demonstrated in Mark Seymour’s presentation at the ASHRAE 2014 Winter meeting (see link to his paper below), this technique can be used to find the cause of the issue and to correct the deployment before it is made. Clearly, therefore, preventing a potential problem through prediction is preferable to fixing it once it has become a reality.

Consider a rack/cabinet which is to have a blade center and three 1U servers installed.

Does it matter how the two equipment types are installed in this cabinet?

Option 1 – Three 1U servers placed on top of a blade center. The configuration is poorly blanked and hot air recirculates under the blade center. This results in recirculated air that is over 27°C entering the IT equipment inlets.

Option 2 – The alternative is to install the 1U servers at the bottom with the blade center . In this configuration, while the there is still recirculation, the temperature of the recirculated air is less than 22°C.

Full Supporting Paper from Mark Seymour’s presentation can be downloaded here: http://www.futurefacilities.com/media/documents/ASHRAE_2014/ASHRAE_2014_Prediction_Is_Better_Than_Cure.pdf