To save energy, some data centers are enclosed in special cases where cold and hot air do not mix. This is called the cold aisle containment. These specialized containments are normal in most hyperscale data centers, and even some smaller ones. They help cool heat-intense servers without consuming too much additional electricity.
This is especially important in hot places like the Middle East. One of the companies in this region taking advantage of the cold aisle is Saudi Aramco, the world’s most profitable company in terms of revenue. They have a massive data center called the Petroleum Engineering Computer Center (ECC) that houses the company’s business information. It was established in 1982, and is a three-story data center providing computing capability to the company’s geologists, geophysicists, and petroleum engineers, helping them explore, develop, and manage Saudi Arabia’s oil and gas reserves.
The ECC is one of those data centers that incorporated cold aisle containments in their facilities because of their energy-saving capacities. In 2015, one of the facility’s five data halls was modified to accommodate the Cold Aisle Containment System. This supported the company’s biggest single deployment so far in the data center. The data facility now hosts 219 racks of servers on a 10,113-square-foot (940-square-meter) floor. Ever since the installation of the cold aisle, the data center hall has not experienced any temperature problems.
What drives Aramco to Install a Cold Aisle Containment?
Over the years, Aramco has grown its clients and customers. This increase has led the company to complete major reconfigurations of their data centers. They deployed several IT hardware and software advanced technologies. Each configuration has doubled the heat being dissipated from the servers. At each step, the company employed measures to minimize the impact of heat on the hardware, ensuring their technology was safe and reliable during each deployment and project implementation.
For example, Saudi Aramco developed a hardware deployment master plan based on a projected three to five years of life cycle and a projected refresh rate to transition to the Cold Aisle/Hot Aisle configuration. This plan left room for advanced planning of space and power source allocation, without compromising existing operations, fund allocations, and material procurement.
What Modeling Software Was Used?
To understand the flow of heat in the facility and better prepare a baseline model for all the data halls, Aramco commissioned a computational fluid dynamics software company. This technology simulates fluid motion and heat transfer using numerical approaches. Most importantly, it performs transient analysis that fits the requirement of the company.
Aramco considered the CFD simulation software as a way to easily identify and address heat stratification and recirculation, and even short-circuiting of cool air. By determining the issues in this way, Saudi Aramco took many precautionary measures, thereby improving capacity management procedures, all while increasing cooling efficiency and optimizing load distribution.
How Does A Temperature and Humidity Monitoring System Help?
The CFD simulation was very helpful in examining the cold and heat flow in the facility. With the results of the simulation in hand, the company’s management team looked for other ways to gather data for more cooling optimization simulations, at the same time, validating the CFD simulation results.
This propelled the company to install a temperature and humidity monitoring system. The first deployment was done in 2008. That included the monitoring of subfloor air supply temperature and hardware temperature monitoring.
Aramco installed three temperature sensors in each cold aisle, for a total of six sensors The sensors were placed at the ends and the middle of the rows. They chose these points so they could get a better understanding of the temperature variance between the subfloor and the highest rack inlet temperature. Also, Aramco monitored the data and ensured that all inlet temperatures were within the recommended ranges set by The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), the leading association seeking to advance the design and construction of heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems.
Having a real-time temperature and humidity monitoring system helped the operation team monitor and record unusual and sudden temperature changes, leaving room for proactive responses and early resolution of potential cooling issues. The monitoring system gathered data that potentially validated the CFD simulations, and for further evaluation and iteration.
Material Selection and Cold Aisle Containment System installation
The facility management team evaluated many products. They also secured and reviewed the material data sheets and submitted them to the Authority Having Jurisdiction (AHJ) for them to evaluate, as well. Out of all the cold aisle products, one stood out, mainly because it was easy to install, and its transparent material addressed not only safety, but also eliminated the need for modifications of the existing infrastructure, which helped minimize execution costs, therefore, helping the bottom line.
After the installation had been completed, moving in and out of the aisle was easy and safe, since people could see through the doors and dividers. Plus, there was no need to modify the data hall lighting because it was not obstructed by the containments. Even the fire suppression system was not compromised, because it had a fusible link and lanyard connector. The only AHJ requirement before deployment was the need to install smoke detectors.
The benefits of the cold aisle containment can be clearly seen in these figures. In Figure 2, both heat and cold diffuse with each other in certain areas, therefore being less efficient in cooling the servers. The installation of cold aisle containments, however, has led to more efficient use of energy. The cold air runs specifically in one place and direction. The hot air is not penetrating the containment. Therefore, both hot and cold are well separated, so there was minimal energy wastage.
This is an image from before the cold aisle installation. The cold air is visibly spreading out and dispersing, along with the hot air and vice versa.
This is the image where the facility only uses the containment on some servers. Not all data servers were enclosed by the cold aisle containment. Compared with the first picture, the heat and cold dispersion has improved greatly. More cold air is being efficiently put to use, and the hot air is outside the contaminants’ range, hence is not reheating the servers.
All data servers are now inside cold aisle containments. This solution has improved the temperature dramatically. High temperatures have been eliminated. Only cold, to mild temperature air is circulating inside the facility. Most importantly, this solution has been the most energy-efficient, because the additional energy used on cooling technologies is concentrated only to cool the servers.
The installation of the Cold Aisle Containment System in one of the biggest companies in the world has greatly affected the overall environment of their energy-heavy data centers. By eradicating the possibility of hot and cold air mixing, the facility has allowed for more efficient cooling unit performance where there’s enough supply of cool air, and a clear exit path for expelled hot air. These technologies are all the more important in hot places such as Saudi Arabia, where ambient temperatures can hover as high as 40°C (104°F). It certainly didn’t help to have a high temperature surrounding the facility, so it was only smart to include energy-efficient solutions such as the cold aisle containment, where every watt of electricity was put to good use.
AKCP provide monitoring solutions tailored for hot and cold aisle containment of data centers. Our thermal map sensors, together with differential air pressure sensors can ensure that intake and exhaust, hot and cold aisle temperatures are within prescribed ranges, and thee differential air pressure between hot and cold aisles is correct. These are displayed in a dedicated sectional aisle view in AKCPro Server, which includes rack access control and asset management tools.