Further to my previous post on my experience with the CoolControl (CC) tiles, I have been spending some time in the Data Centre this morning with Daxten again looking at some options for hot aisle containment.
Over the weeks, I have been installing the grommets in the tiles below the cabinets in order to block cold air from mixing with hot air inside the cab. This has proven to be very effective. However, some experimentation today has proven even more valuable.
In my last blog I mentioned that I had installed some of the CC tiles to disrupt the air flow in the cold aisle, but that due to the velocity of the air so close to the grilled tile, the air was not travelling up the face of the cabinet, but rather bouncing back at the CRAHs. I have a test piece of pleniform with holes strategically placed in it to provide a buffer against the flow of air to slow it down to 30% of its normal velocity, however, I haven’t found time to fit it yet. On investigation, we noticed that the delta T between the top of the rack and the bottom was between 4-6 Degrees Centigrade. I have the set point at the CRAH’s set to 24 Degrees C. And we also found that the ordinary grilled tiles (I had left them in spaced between the CC tiles) were exerting a negative downward pressure that prevented cold air from reaching the cabinets!
The obvious thing was to replace the grilled tiles with blank tiles and the temperatures reduced to 17-19 Degrees C at the bottom and 19-21 degrees C at the top. This suggests that I can now start to play with upping the set point back at the CRAHs to raise the dry bulb inlet temperature to 25 Degrees C. Replacing the grilled tiles seemed counter-intuitive, however it made a significant positive difference!
More to come when I get round to looking at the pleniform….