Data racks in a data center allow you to organize various pieces of IT hardware into standard and custom assemblies. Such equipment typically includes servers, flash modules, routers, network switches, UPS, PDUs and cable managers. In this manner, the data racks in a data center make it possible to avail the resources that everyday applications rely upon for fast service delivery.
However, the needs of a data center extend beyond the maximum utilization of valuable space. This article looks at how to realize efficiently cooling in the modern data center.
Efficiently Cooling Rack-Mounted IT Resources
The myriad of rack-mounted equipment in a data center generate a lot of heat in the course of normal operation. A data center must, therefore, incorporate a cooling system to help maintain optimum working temperature.
Most data centers make use of raised floor cooling designs which utilize under-floor fans to direct cool air on to the rack-mounted equipment. However, raised floor cooling systems can only deliver enough cool air to support a maximum of 6 kilowatts of equipment per rack.
Configurations with higher cooling requirements will require you to install specialized cooling systems. Such systems require additional cooling fans to enhance air circulation within the data center. However, installing and maintaining specialized cooling equipment is both time consuming and expensive. Fortunately, the advent of HACS and CACS cooling systems has made it possible to overcome the limitations of traditional cooling systems.
HACS and CACS are acronyms for Hot Aisle Containment System and Cold Aisle Containment System. These thermal containment systems do not replace the traditional raised floor cooling system but are implemented alongside the older system. The working principle behind HACS and CASC has to do with the separation of hot and cool air streams within a server room. This ensures that your cooling system runs with greater predictability and efficiency.
How HACS and CACS Work
A Hot Aisle Containment System is composed of doors that cap the ends of server rows. These doors are mounted onto the racks at the ends of the rows. To help realize a fully enclosed aisle, transparent ceiling tiles are used to cover the top of the racks. This way, HACS isolate the hot aisles from the rest of the room.
The HACS works by first capturing all the hot air from the IT equipment within the enclosed aisle. This heated air is then directed to the cooling units located under the floor of a typical data center. These cooling units extract all the heat from the air and return cool air. It is possible to use this thermal containment system as a standalone cooling system in small data centers.
A Cold Aisle Containment System is usually used to add notable efficiency to traditional cooling systems. As with HACS, a CASC cooling system also has an enclosed space between server rows. Unlike hot aisle containment systems, cold aisle containment solutions work by directing hot air away IT equipment to the rest of server room.
Comparison of HACS and CACS
A cold aisle containment system exhibits limitations when compared to hot aisle containment systems. By containing the hot air, HACS in-row cooling units are able to capture all the heat from the air. Since HACS eliminates the mixing of air within the room, the cooling units in this system can return much cooler air to IT equipment. Hot aisle containment systems also minimize variation in the speed of coiling fans of in-row cooling units. As such, HACS allows you to realize greater energy savings.
CACS systems, on the other, only keep the air within the aisle cool by directing this hot air into the room. The outcome is that the air in the room gets hotter, which means the room cooling system has to do more work. Overall, HACS offer a greater level of cooling efficiency compared to CACS.
Thermal containment systems make it possible to overcome the limitations of traditional raised floor cooling systems. HACS and CACS make it possible mount equipment with power outputs of up to 30 kilowatts. The fact that 80% of data centers are looking to install hot aisle and cold aisle containment systems is testament to the cooling and energy usage benefits that these systems offer.
