Comments on: So you think you understand your data center? http://www.thehotaisle.com/2010/07/07/so-you-think-you-understand-your-data-center/ Fresh Thinking on IT Operations Mon, 06 Feb 2012 16:02:00 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Steve O'Donnell http://www.thehotaisle.com/2010/07/07/so-you-think-you-understand-your-data-center/comment-page-1/#comment-7397 Steve O'Donnell Thu, 08 Jul 2010 19:13:20 +0000 http://www.thehotaisle.com/?p=1984#comment-7397 Thanks for a great response Larry. A couple of additional points - most high density filters are removable. In our case the filters simply flip over when the airflow runs in reverse. Second issue is that not all technical spaces have a false ceiling. The best policy is to use CRACs with dampers. Steve Thanks for a great response Larry. A couple of additional points – most high density filters are removable. In our case the filters simply flip over when the airflow runs in reverse. Second issue is that not all technical spaces have a false ceiling.

The best policy is to use CRACs with dampers.

Steve

]]> By: Larry Mainers http://www.thehotaisle.com/2010/07/07/so-you-think-you-understand-your-data-center/comment-page-1/#comment-7396 Larry Mainers Thu, 08 Jul 2010 15:42:32 +0000 http://www.thehotaisle.com/?p=1984#comment-7396 It has been my experience that air moving back through a CRAC unit due to it being idle is not like open raised floor tiles. This is due to the fact that the subfloor static pressure must push the air up through the fans, coil, and high density filters. Another important factor is that this air (without a CRAC extension into the drop ceiling void) would be emptied out into the ambient air and not a hot-zone. Most data centers mix hot and cold air to reach an homogenized supply temperature thus supply air through the idle AC unit would have a modest affect on the overall cooling. That is, of course, unless the AC unit represents more then 35% of the supply. The best way to fix this would be to employ either hot or cold aisle containment. It has been my experience that air moving back through a CRAC unit due to it being idle is not like open raised floor tiles. This is due to the fact that the subfloor static pressure must push the air up through the fans, coil, and high density filters. Another important factor is that this air (without a CRAC extension into the drop ceiling void) would be emptied out into the ambient air and not a hot-zone. Most data centers mix hot and cold air to reach an homogenized supply temperature thus supply air through the idle AC unit would have a modest affect on the overall cooling. That is, of course, unless the AC unit represents more then 35% of the supply. The best way to fix this would be to employ either hot or cold aisle containment.

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