Understanding Hot Aisle Containment

Posted by Instor on Nov 7, 2017 9:00:00 AM

The data center industry is always on the lookout for better ways to manage energy consumption. And there are good reasons for it. According to a New York Times article, Google consumed as much electricity as the city of San Francisco in 2015. Of course, optimizing server room cooling is one of the known ways to improve data center energy efficiency. And hot aisle containment (HAC) is considered an effective cooling method.


The Benefits of Hot Aisle Containment in Data Centers

What is Hot Aisle Containment? 

In traditional data centers, servers are organized into rows and columns to allow the hot air exiting the servers into particular aisles. This organization creates hot aisles and cold aisles. Air conditioning collects the hot air at the top, cools it down and pumps the cold air through the raised floors. The floors have fans or perforated tiles to allow the passage of air.

The traditional cooling systems depend on the natural movements of the air to collect the hot air. They are designed with over capacity to handle unpredictable air movements and the mixing of temperatures. Also, these systems can end up with hotspots if the air circulation is not optimum.

In HAC, the hot aisles are contained using doors and roof tiles. For in-row cooling, the cooling units are placed along the rows. For central cooling, ducts are used to lead the hot air to the computer room air handler (CRAH). The containment of hot air leads to cooling optimization and less energy use.

Benefits of HAC

 HAC systems have a lot of benefits over traditional methods of cooling:

  • Due to containment, there is no mixing of cold and hot air, so the air conditioning systems can efficiently collect the hot air for processing.
  • Most of the data center is cold. Therefore, data center managers don't have to worry about any non-rack equipment. The cold temperature will ensure those devices are running efficiently.
  • Space can be used more efficiently. The open area of the system is cold, so data center workers can be stationed without worrying about OSHA or ISO 7243 guideline violations.
  • The aisle containments are designed to work with the racks so they can be installed without creating separation for fire suppression systems. Managers can create hot aisle containers while meeting the current fire suppression requirements and codes.

Challenges of HAC

There are a few challenges that data center managers should be aware of:

  • HAC system installations can be more expensive than other systems, translating to higher upfront costs.
  • The temperatures in the hot containments are going to be higher than traditional hot aisles. This could make things slightly less comfortable for workers when they have to deal with hot aisle sides of the servers.

Comparing Hot Aisle with Cold Aisle Containment (CAC)

A cold aisle containment systems reverse the process. Instead of hot aisles, the cold aisles are contained using doors and roof tiles. The computer room air handler processes the air from the whole data center space.

CACs are not as efficient as HACs. Because the hot air from the equipment goes into a wider space in a CAC setup, the air handlers are not able to handle the temperature as efficiently as in HAC system. Also, due to room temperature increase in a CAC, it isn’t reliable for non-rack equipment. However, CAC installation is cheaper and they are generally used to enhance traditional cooling systems.

HAC systems can improve data center energy efficiency and save managers a lot of money. However, data center managers should look into their budgets and plan ahead. It’s also necessary to take a long-term view and figure out the time it will take to get a return on investment. CAC can work as a cheaper alternative for those who are on a tighter budget. But HAC systems are recommended for better performance.


Go To >>> Data Center Fit Up Estimator


Topics: Hot & Cold Aisle Containment