Aisle containment plays a crucial role in the modern data center. This system prevents hot and cold air from mixing with each other. Studies show that up to 50% of airflow is being wasted in typical data centers. This is because it bypasses the equipment that it is intended to cool, and the air goes back directly to the CRAC units.
Having a data center containment system allows for optimum equipment performance. Additionally, it also improves the energy efficiency inside the facility by reducing hot spots and maximizing the cooling potential of AC units. Through this, the need for additional CRAC units while increasing server density may be eliminated.
High costs and energy consumption have led data centers to review hot-air and cold-air data center containment strategies. As the strategy of separating hot and cold air is recognized as a promising measure to increase energy efficiency in data centers. Through aisle containment, IT inlet temperatures become uniform, and it also eliminates the hot spots usually found in un-contained data centers.
There are two data center containment methodologies, hot-aisle, and cold-aisle containment. Both containment allows substantial energy savings compared to un-contained systems. The energy saved can be about 30% or higher if the cold and hot air flow are prevented from mixing. Both containment strategies are equally efficient if they are done correctly and adequately.
Hot Aisle Containment System
Through a Hot-Aisle Data Center Containment system, the hot aisle is enclosed. With the hot aisle enclosed, a large amount of cold air is supplied to the rest of the data center. Sometimes through raised access flooring, overhead ducting of simply flooding the data center with cold air. This air finds its way to the equipment and servers. It consists of a physical barrier that directs hot exhaust airflow to the AC return.
Hot aisle data center containment also allows thermal override, which is an added advantage. Thermal override enables the data center to remain stable for a period of time if cooling systems fail, as there is a reservoir of cold air that can maintain supply temperature for a limited time until cooling is restored.
Legacy Hot Aisle Containment vs. Modular Hot Aisle Containment
With legacy hot aisle containment, the hot air is fully contained. It happens when hot air is ducted into the ceiling plenum, and then it returns to the cooling units, which are also ducted to the ceiling unit. The rest of the room remains cold while the hot air is fully contained. The tile placement in this setup is not critical, which allows air to flow where it is needed freely. Any leakages from air conditioners are also better managed since it goes into the general space for cooling. Due to this, hot aisle containment tends to be more efficient. It also provides a cooler working environment for employees.
Meanwhile, for Modular Hot Aisle Containment, there is no full duct or chimney to the ceiling plenum. Still, it has almost the same benefits as a legacy hot aisle containment. In optimizing data centers, the amount of air being delivered to the equipment is critical. The conditioned air flowing through the cooling units must be balanced with the amount of air flowing through the IT equipment. However, if there is excess conditioned air flowing through the room, a bypass airflow will occur regardless of whether you have full or partial hot aisle containment.
Cold Aisle Containment System
In Cold Aisle Data Center Containment, the cold air is enclosed in the aisle. The rest of the data center becomes a large hot-air return plenum. This containment involves a physical barrier that enables the supply air to flow inside the cold aisle. Through this a predictable and uniform temperature is made possible at server air in-take. Cold aisle data center containment systems are often used on slab floors, for in-row cooling projects.
Legacy Cold Aisle Containment vs. Modular Cold Aisle Containment
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Cold Aisle Containments tend to be less preferable than Hot Aisle Containments. Since cold air is contained, this leads the rest of the room to have a temperature of around 80°F or 90°F. When personnel opens the door, intolerable temperatures are experienced. Though Legacy Cold Aisle Containments were easier to deploy, they are often not chosen as a preferred containment system. Due to this, their environments are also not utilized to showcase their full capability.
For Modular Cold Aisle Containment, there is a gap on the top enclosure of the aisle. The gap, however, does not affect the balance between the supply and demand of air. Some of the core benefits of Modular Cold Aisle Containment are flexibility and low costs. Since the doors and baffles attach magnetically, they can be installed and removed by staff without the assistance of third-party vendors.
Airflow Management vs. Cooling Optimization
Airflow management and cooling optimization sound like similar terms, but they are different. Airflow management refers to the process of managing the airflow in a computer room. This includes solutions such as blanking panels, grommets, and containment. Meanwhile, cooling optimization refers to the process of adjusting the cooling system controls like increasing temperature set points or decreasing fan speeds. Airflow management can improve the air temperature intake of IT equipment. However, it is with cooling optimization that energy efficiency will be improved. Furthermore, an optimized cooling infrastructure can reduce operating costs and improve cooling capacity.
Steps for Data Center Cooling Optimization
Some data center managers may have a “colder is better” attitude with regard to data center management. This is because the greater airflow and the cooler the temperature, the easier it is to meet customer service level agreements. However, an unnecessarily cold temperature may lead to wastage and increased energy bills. Below are some steps to optimize the data center’s cooling:
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Implement Containment Systems to Separate Incoming Air from Exit Air
When this is done, it allows data the maintenance of desired temperatures which can help meet service level agreements. When the air is hotter, heat rejection becomes more efficient.
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Determine the Supply Temperature That will Run the IT Equipment
The ideal temperature range is between 65° to 80°F. If the data center is running at higher temperatures, the server fans will ramp up and consume more energy.
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Utilize a Variable Capacity System that can Adjust to the IT load
In legacy data centers, fans often produce too much air. Therefore, leading to unnecessary consumption of electricity. The use of a variable capacity system will eliminate wasted energy through air consumption and address reliability problems caused by not producing sufficient air.
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Make Sure the Proper Controls are in Place for Data Center Optimization
In setting up data center controls, it is important to measure temperatures in the aisles and in front of the servers. The cooling equipment should also be controlled in order to maintain a sufficient amount of heat rejection.
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Utilize Economization in Order to Lower Costs and Reduce Power Consumption
One example of this is bringing outside air in order to reject heat without the use of mechanical refrigeration.
AKCP Rack+ Data Center Sensors
The room’s thermal parameters must be continually checked and changed to guarantee optimal performance, both to enhance efficiency and to avoid downtime. A carefully monitored containment system, for example, allows cooling systems to be adjusted to a higher supply temperature, saving energy and increasing cooling capacity while remaining within acceptable operating temperatures. Uncontained cooling systems, on the other hand, are limited to a considerably lower set point than what is required by IT equipment to avoid hot spots. This sort of overcooling technology works, however it is inefficient in terms of energy use.
A properly monitored containment system is a tremendous reduction in hot spots. However, no system is perfect, and monitoring sensors should still be in use to provide ample warning in the unlikely event that a hot spot begins to form. Of course, an optimum monitoring solution would also be providing data so that data center operators have the critical information necessary to increase their efficiency.
AKCP is the world’s leader in SNMP-based Data Center Monitoring Solutions. With over 200,000 installations worldwide, you can count on us to monitor and protect your Data Center.
Add any of the below sensors to your cabinet to build a smart rack solution. Sensors connect to sensorProbe+ base units.
AKCP Rack+ Data Center Sensors
Intelligent Hot and Cold Aisle Containment
Cold Aisle
Place dual temperature and humidity sensor in your cold aisle to check the aisle temperature is not too hot or wasting energy by being too cold.
Cabinet Hotspots
Monitor temperature at the front and rear, top middle and bottom of the IT cabinet, as well as the temperature differential from the front to rear, T value.
Differential Pressure
Monitor for proper pressure differentials to check adequate airflow from cold to the hot aisle. Run more efficiently with correct pressure differential to prevent back pressure and hot air mixing back to the cold aisle.
Water Leaks, Access Control, and Sensor Status Lights
The addition of rope water sensors underneath raised access flooring, rack level, and aisle access control, and sensor status lights complete the intelligent containment monitoring system.
Containment Maps in AKCPro Server DCIM
AKCPro Server includes dedicated desktops for displaying your containment monitoring system in an easy and visual interface. Install AKCPro Server on your own server, or take advantage of the built-in server that is embedded on every L-DCIM.
Reference Links:
https://www.tateinc.com/en-us/data-center-containment
https://www.missioncriticalmagazine.com/ext/resources/MC/Home/Files/PDFs/WP-APC-Hot_vs_Cold_Aisle.pdf
https://www.upsite.com/blog/what-is-cooling-optimization/
https://www.youtube.com/watch?v=xzwA6dUpXO0
https://www.42u.com/hot-cold-aisle-containment-benefits-challenges-andre/
https://edge.siriuscom.com/infrastructure-operations/5-steps-to-optimizing-your-data-center-cooling
https://www.sunbirddcim.com/glossary/data-center-containment
