Cooling is today’s problem

Despite hot/cold aisle layouts becoming common and the adoption of sealing cable cutouts and using blanking panels, the cooling problem persists. In fact, 39% of data center managers expect to be out of cooling capacity in the 2009 to 2010 period according to recent surveys. The culprit is the continued mixing of warm return air with cool supply air. The open architecture above and around the hot and cold aisles allows the mixing and is the primary source of the waste.

Containment is today's low hanging fruit

Cold aisle and hot aisle containment stops mixing and allows cooling units to run at reduced capacity while still achieving ideal cooling conditions. Industry analysts suggest effective containment of the hot or cold aisles will provide, for most users, the single largest payback among any of the current data center best practices.

What is Containment?

Aisle containment is a data center efficiency practice which utilizes physical barriers (PolarPlexTM Curtains or Panels) at the front, back, and top of the aisles to eliminate cold air loss and to stop hot air from penetrating into the cold aisle. The reduction in air mixing increases the return air temperature to the CRAC units. This raises the delta-T across the CRAC units, resulting in more efficient cooling. The isolation also eliminates hot spots and makes the supply air temperature more uniform across the server inlets. This increases reliability while allowing the supply air set points to be safely increased.

 

 

Hot Aisle versus Cold Aisle Containment

As more and more data centers install containment solutions one key question will be whether to contain the hot aisle or the cold aisle. Some of this will simply be answered by the site’s cabling and cooling architecture. But more often, there will be a choice. Arguments in favor of cold aisle containment include better efficiency performance, a more direct cooling air path, and positive air pressure keeping hot air out. Arguments in favor of hot aisle containment include longer run through if there is a cooling failure and a more comfortable working environment.

Panels versus Curtains

Site layout, floor type, cooling architecture, and ceiling height are key drivers that determine if softwall curtains or rigid panels are best. Curtains and panels can be deployed in a variety of ceiling types. For dropped ceilings, curtains are easily suspended from the grid system and are the most common choice. In open ceilings the existing structure or additional unistrut framing is used for securing curtains or panels. In tall ceilings panels secured to and supported by the racks is a common option.

 

 

Fire Safety

Installing a barrier inside the data center typically requires addressing fire detection and suppression. There are solutions for complying with fire safety codes for containment systems that have been accepted by fire marshals and insurance auditors. The specific solution depends on the type of detection (smoke, VESDA) and suppression (clean agent, water) and how it is deployed in the site. Polargy can help design an effective containment system that considers the site architecture and that meets fire code.