{"id":2484,"date":"2024-09-08T18:42:08","date_gmt":"2024-09-08T10:42:08","guid":{"rendered":"https:\/\/www.datacenterair.com\/?p=2484"},"modified":"2024-09-08T18:45:22","modified_gmt":"2024-09-08T10:45:22","slug":"improving-datacenter-airflow","status":"publish","type":"post","link":"http:\/\/datacenterair.com\/improving-datacenter-airflow\/","title":{"rendered":"Improving datacenter airflow"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_69_1 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"http:\/\/datacenterair.com\/improving-datacenter-airflow\/#Part1_background\" title=\"Part1: background\">Part1: background<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"http:\/\/datacenterair.com\/improving-datacenter-airflow\/#Part2_Chart_Description\" title=\"Part2:Chart Description\">Part2:Chart Description<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"http:\/\/datacenterair.com\/improving-datacenter-airflow\/#Part3_How_do_I_read_this_chart\" title=\"Part3:How do I read this chart?\">Part3:How do I read this chart?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"http:\/\/datacenterair.com\/improving-datacenter-airflow\/#Part4_What_does_this_data_tell_us\" title=\"Part4:What does this data tell us?\">Part4:What does this data tell us?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"http:\/\/datacenterair.com\/improving-datacenter-airflow\/#Part5_Lets_start_taking_action_on_the_data\" title=\"Part5:Let\u2019s start taking action on the data\">Part5:Let\u2019s start taking action on the data<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"http:\/\/datacenterair.com\/improving-datacenter-airflow\/#Part6_What_does_a_graph_look_like_indicating_minimal_mixing\" title=\"Part6:What does a graph look like indicating minimal mixing?\">Part6:What does a graph look like indicating minimal mixing?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"http:\/\/datacenterair.com\/improving-datacenter-airflow\/#Part7_But_I_want_my_airflow_to_be_perfect\" title=\"Part7:But I want my airflow to be perfect\">Part7:But I want my airflow to be perfect<\/a><\/li><\/ul><\/nav><\/div>\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Part1_background\"><\/span>Part1: background<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>This data center has\u00a0poor airflow management (lots of mixing issues)<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img fetchpriority=\"high\" decoding=\"async\" width=\"822\" height=\"437\" src=\"https:\/\/www.datacenterair.com\/wp-content\/uploads\/Picture1.png\" alt=\"\" class=\"wp-image-2485\" srcset=\"http:\/\/datacenterair.com\/wp-content\/uploads\/Picture1.png 822w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture1-300x159.png 300w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture1-768x408.png 768w\" sizes=\"(max-width: 822px) 100vw, 822px\" \/><\/figure>\n\n\n\n<p>This data center has efficient airflow management (little to no mixing issues)<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"822\" height=\"437\" src=\"https:\/\/www.datacenterair.com\/wp-content\/uploads\/Picture2.png\" alt=\"\" class=\"wp-image-2486\" srcset=\"http:\/\/datacenterair.com\/wp-content\/uploads\/Picture2.png 822w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture2-300x159.png 300w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture2-768x408.png 768w\" sizes=\"(max-width: 822px) 100vw, 822px\" \/><\/figure>\n\n\n\n<p><em>Big bubbles in red = mixing<\/em><\/p>\n\n\n\n<p><em>Big bubbles in green = no mixing<\/em><\/p>\n\n\n\n<p>Feel free to stop reading at this point, because this is really all you need to know about mitigating poor airflow management in your facility. But, if you are curious as to how this analysis was achieved, and how analytics like this can be used to turn mountains of data into actionable information, read on.<\/p>\n\n\n\n<p>The following bubble chart displays the server inlet temperatures collected every hour at the top and bottom of 30 racks, over 7 days.&nbsp; The chart contains 10,260 individual data points, accordingly.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Part2_Chart_Description\"><\/span>Part2:<strong>Chart Description<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>The Y-axis on this chart indicates the difference between the top and bottom temperature points.\u00a0 I to refer to this as the delta-T.\u00a0 Mathematically it is: top temperature \u2013 bottom temperature<\/p>\n\n\n\n<p>The X-Axis lists each of the 30 racks (labeled 1 through 30).<\/p>\n\n\n\n<p>The bubbles indicate the delta-T at each rack.&nbsp; There are multiple bubbles for each rack because the delta-T changes over the course of the 7-day measurement period.<\/p>\n\n\n\n<p>The size of the bubble indicates the length of time each rack maintained that particular delta-T. &nbsp;Larger bubbles indicate more time and smaller bubbles indicate less.<\/p>\n\n\n\n<p>The colors of the bubbles are displayed differently side by side for visual acuity only.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"916\" height=\"487\" src=\"https:\/\/www.datacenterair.com\/wp-content\/uploads\/Picture3.png\" alt=\"\" class=\"wp-image-2487\" srcset=\"http:\/\/datacenterair.com\/wp-content\/uploads\/Picture3.png 916w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture3-300x159.png 300w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture3-768x408.png 768w\" sizes=\"(max-width: 916px) 100vw, 916px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Part3_How_do_I_read_this_chart\"><\/span>Part3:How do I read this chart?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Start with Rack 1 which displays the dark blue bubbles to the far left.\u00a0 During the 7-day date range, Rack 1 had a delta-T (top temperature \u2013 bottom temperature) that fluctuated between 4\u00b0F and 6\u00b0F.\u00a0 The majority of the time the delta-T for Rack 1 was 4\u00b0F, indicated by the larger-sized bubble.<\/p>\n\n\n\n<p>Now look at Rack 9.&nbsp; The delta-T for Rack 9 fluctuated between 4\u00b0F and 14\u00b0F, but it spent most of the time at 12\u00b0F.<\/p>\n\n\n\n<p>Rack 12 spent the entire time (i.e. all 7 days) time at -2\u00b0F.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Part4_What_does_this_data_tell_us\"><\/span>Part4:What does this data tell us?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>In most data centers, we expect the temperature at the top of the rack to be hotter than the temperature at the bottom of the rack. This is simply because hot air rises.\u00a0 This will even be the case in an overhead air distribution environment (but perhaps not as much so as an underfloor distribution).\u00a0 However, since we are comparing the data to the rest of the temperatures in the facility, a marker of good analytics, this analysis will provide the same insights in any type of environment.<\/p>\n\n\n\n<p>This particular facility had underfloor air distribution. We would expect the delta-T to be somewhere between 0\u00b0F \u2013 8\u00b0F.\u00a0 Said another way, we wouldn\u2019t expect the top of the rack to be more than 8\u00b0F hotter than the bottom of the rack.\u00a0 And certainly, we wouldn\u2019t expect the bottom to be hotter than the top, which would be indicated by negative values.<\/p>\n\n\n\n<p>The green region indicates the expected range of delta-Ts.&nbsp; The red region indicates delta-Ts outside of this expected range.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"847\" height=\"449\" src=\"https:\/\/www.datacenterair.com\/wp-content\/uploads\/Picture4.png\" alt=\"\" class=\"wp-image-2488\" srcset=\"http:\/\/datacenterair.com\/wp-content\/uploads\/Picture4.png 847w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture4-300x159.png 300w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture4-768x407.png 768w\" sizes=\"(max-width: 847px) 100vw, 847px\" \/><\/figure>\n\n\n\n<p>It\u2019s clear that over the course of the 7-day period there were some delta-Ts significantly outside of the expected range.<\/p>\n\n\n\n<p>The beauty of this analysis is that not only are those aberrations clear, but it also becomes simple to identify the specific culprits by highlighting which racks have big bubbles in the red region.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"847\" height=\"449\" src=\"https:\/\/www.datacenterair.com\/wp-content\/uploads\/Picture5.png\" alt=\"\" class=\"wp-image-2489\" srcset=\"http:\/\/datacenterair.com\/wp-content\/uploads\/Picture5.png 847w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture5-300x159.png 300w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture5-768x407.png 768w\" sizes=\"(max-width: 847px) 100vw, 847px\" \/><\/figure>\n\n\n\n<p>The racks highlighted in gray on the X-Axis have delta-Ts that lie outside our expected range.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Part5_Lets_start_taking_action_on_the_data\"><\/span>Part5:Let\u2019s start taking action on the data<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Why are the delta-Ts for these racks outside our expected range?<\/p>\n\n\n\n<p>There could be a number of reasons, however it\u2019s usually an indication of mixing.&nbsp; Some reasons might include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>No blanking panels<\/li>\n\n\n\n<li>Too many or too few perforated tiles<\/li>\n\n\n\n<li>Too much or too little airflow<\/li>\n\n\n\n<li>IT equipment that is installed backward (and blowing hot air on the bottom sensor)<\/li>\n\n\n\n<li>Racks that do not conform to a cold aisle\/hot aisle layout<\/li>\n<\/ul>\n\n\n\n<p>Analytics may not always be able to tell you why something is occurring, but good analytics can indicate where your problems lie so you know where to focus your attention.&nbsp; Visually inspecting the racks highlighted in gray will probably reveal the root cause of the mixing issue.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Part6_What_does_a_graph_look_like_indicating_minimal_mixing\"><\/span>Part6:What does a graph look like indicating minimal mixing?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Re-running the analysis after implementing some simple airflow improvements for the culprit locations will look more like this:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"847\" height=\"449\" src=\"https:\/\/www.datacenterair.com\/wp-content\/uploads\/Picture6.png\" alt=\"\" class=\"wp-image-2490\" srcset=\"http:\/\/datacenterair.com\/wp-content\/uploads\/Picture6.png 847w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture6-300x159.png 300w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture6-768x407.png 768w\" sizes=\"(max-width: 847px) 100vw, 847px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Part7_But_I_want_my_airflow_to_be_perfect\"><\/span>Part7:But I want my airflow to be perfect<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Then see if you can achieve this:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"847\" height=\"449\" src=\"https:\/\/www.datacenterair.com\/wp-content\/uploads\/Picture7.png\" alt=\"\" class=\"wp-image-2491\" srcset=\"http:\/\/datacenterair.com\/wp-content\/uploads\/Picture7.png 847w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture7-300x159.png 300w, http:\/\/datacenterair.com\/wp-content\/uploads\/Picture7-768x407.png 768w\" sizes=\"(max-width: 847px) 100vw, 847px\" \/><\/figure>\n\n\n\n<p>With the right rack layout, containment strategy, floor\/rack\/cable seals, blanking panel management, perforated tile layout, and cooling control, this is achievable.<\/p>\n\n\n\n<p>And even better, you can see it, track your progress, and prove it to your management or colo clients.<\/p>\n\n\n\n<p>I challenge you to get there.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Part1: background This data center has\u00a0poor airflow management (lots of mixing issues) This data center has efficient airflow management (little to no mixing issues) Big bubbles in red = mixing Big bubbles in green = no mixing Feel free to stop reading at this point, because this is really all you need to know about [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":1328,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"rank_math_lock_modified_date":false,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center 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