Industry Insights

The Importance of Airflow Management in Your Physical Infrastructure

Wednesday, January 3, 2018 | by Danielle Russo

Won’t you step into the freezer…It’s gonna be cold, cold, cold…or not?

Welcome to 2018!  With 90% of the US bringing in the new year in below freezing temperatures, what better time to discuss one of my favorite topics: Cooling and Airflow Management!  While it is crucial to keep ambient operating temperatures cool in your mission critical facility, we are not looking for the deep freeze temperatures that most are experiencing outdoors this week. 

The American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) has been tracking and defining allowable temperatures for data centers over the past 14 years.  Data published through ASHRAE has transformed the legacy data center from an inefficient ice-box to a facility with more moderate temperatures and smart design, while still maintaining crucial uptime.  In the past, one may have grabbed a jacket before heading into their data center; however, as of 2011, ASHRAE recommended operating temperatures ranging from 64.4-80.4°F (18-27°C).1


Not only have recommended data center temperatures increased over time, but we have also learned to leverage “free-cooling” through air-side economization.3Initially, many were reluctant to deploy air-side economization due to dry outdoor air in colder climates.  However, two main changes took place which helped popularized the idea of free-cooling systems.  First, thermal systems were adapted to accommodate for this low-humidity input air.  Meanwhile, ASHRAE lowered the acceptable operating humidity standards for a data center.  The combination of these two events resulted in the implementation of free-cooling systems in many cooler climates world-wide. 

In order to maintain ASHRAE recommended operating temperatures, realize operating efficiencies/savings, and appropriately leverage any potential free-cooling opportunities, it is crucial to prevent the mixing of hot air and cold air.  This is where proper design of your physical infrastructure and airflow direction is paramount. 

How Does Your Physical Infrastructure Affect Cooling?

In legacy data centers, it was common practice to send cold air from computer room air conditioning units (CRACs) through plenums under a raised floor to cool the entire room.  As thermal and energy efficiencies grew in importance and financial constraints became more stringent, we learned to manage the path of the airflow to achieve a more efficient cooling system. 

Hot/cold aisle containment is more common than ever, and proper architecture of your cabinet systems will allow you to optimize your efficiencies and maximize your cooling potential.  Your physical infrastructure is the main line of defense in the separation of cold supply air and hot exhaust air.  By preventing recirculation you can ensure consistent delivery of airflow and constant temperatures to the IT equipment.

For example, the use of bottom panels, floor seal brackets, and seal kits eliminate the chance of recirculation and bypass airflow in and around the cabinets.  As depicted above, we can take this even one step further:  Vertical air dam kits and half-depth divider panels create a common plenum, moving the hot aisle inside the back of the racks.   Many of these Legrand solutions for the LX cabinet system feature tool-less installation and removal, for quick and easy deployment and adjustments. 

Side Breathing Switch Cooling

Many network IT equipment manufacturers have introduced “side-to-side” airflow cooling as a way to increase port density while taking up less vertical space.4  When this equipment is deployed in a traditional hot/cold aisle (front-to-rear) data center configuration, several airflow management challenges arise from the opposing airflow patterns. 

Legrand offers several solutions to address this issue, including airflow baffles that re-direct side-to-side airflow into a front-to-rear airflow pattern between two cabinets.  Side cars allow side breathing equipment to be placed anywhere in the aisle.  In addition, tool-less front-to-rear blanking panels attach to the rails to eliminate recirculation. 

When utilizing the correct available airflow management options, the thermal system of your data center can operate much more efficiently, resulting in significant OPEX savings.  The heat maps of various cabinet systems shown below illustrate the advantages of using the LX cabinet airflow baffles to purposefully redirect side-to-side switch cooling in your front-to-rear airflow design.

Cool Smarter, Not Harder

As the demands on data centers are pushing for an increase in efficiencies and a reduction in OPEX, it is crucial to leverage your physical infrastructure system to optimize your thermal management system.  The Legrand LX cabinet solution was designed specifically to tackle your unique data center challenges through innovative design and sustainable solutions. 



ASHRAE. 2008. Thermal Guidelines for Data Processing Environments, 2nd Edition.

TC 9.9. 2011. “Thermal Guidelines for Data Processing Environments.”

ASHRAE “Free Cooling for Data Center”

AFCO: “The rise of the side-breathing switch and what this means for your cabinet airflow management”

Legrand LX Cabinet System