Designs with perforated tiles on a raised floor

Working with plenum velocities The Plenum view of the data center floor layout shows plenum airflow velocities and perforated tile airflow rates for rooms with raised floor cooling systems. The tile airflow rate is indicated by tile color and is also shown in the pop-up box when the cursor is placed over a tile. The color coding of tile(s) is done based on how airflow is divided between the tiles relative to each other. The tile(s) with the lowest airflow is blue. The tile(s) with highest airflow is painted red. The tile(s) in the middle in terms of airflow is green. 102237283_360037995814.png You can relate the plenum velocities to the length or color of the arrows by changing the settings in Tools>Preferences>Plenum Velocities. 102237273_360037995814.png The pressure is generally high in areas of low velocity and vice versa. When perforated tiles are placed near CRACs in regions of high velocity, these tiles will generally deliver less than the average tile airflow rate and may even result in negative airflow, i.e. airflow directed down into the plenum. The parameters that affect tile airflow uniformity and suggested design practices are shown in the table. You can set the plenum depth in the Room Properties, accessed by right-clicking the room and setting the raised floor height in Properties>Floor. You can add two types of perforated tiles (25% and 56% open area) to the layout from the Genomes pane. The raised-floor leakage is defined as the fraction of (downflow) CRAC airflow which does not enter the room through perforated tiles but escapes the plenum (but still into the room) through other openings such as cable cutouts and leakage paths around tiles. Typical data centers may have leakage values in the 10-50%+ range. You can set the leakage airflow by right-clicking the room layout and using the leakage slider in Properties>Cooling. 102237279_360037995814.jpg

Working with plenum pressure The Floor Plenum Pressure overlay of the data center floor layout shows a color-coded overview of the pressure distribution. This is an advanced and specific view of the plenum for the type of data center layout that includes a raised floor environment, perforated tiles, and downflow CRACs. Unlike the Cooling overlay, the plenum overlays only consider room-based cooling. Note Row-based cooling units, racks and other heat generating equipment are not taken into account in these calculations. The color scale represents the various pressure differences between the air above and below the raised floor. The numbers in the pressure scale automatically adjust to include the values in the data center layout. You can use this overlay to get an overview of the positions in the floor layout that are eligible for positioning the perforated tiles based on your insight into the plenum pressure. When you add tiles to the floor layout, you can use this insight to position perforated tiles where the pressure is high and preferably not too close to a downflow CRAC. 102237745_360037995794.png

Designs with perforated tiles on a raised floor "Perforated tiles on a raised floor often deliver substantially more or less airflow than expected, resulting in inefficiencies and even equipment failure due to inadequate cooling. In this paper, the impact of data center design parameters on perforated tile airflow is quantified and methods of improving airflow uniformity are discussed." Source: Airflow Uniformity through Perforated Tiles in a Raised-Floor Data Center (White Paper 121) Read the full White Paper here.