Data center containment and control drives energy efficiency
Datacenter Dynamics, May 11, 2016. Image credit:
Containment and Control is an element in the strategy to improve the efficiency of data center cooling systems by isolating either the heat produced by IT equipment (hot aisle containment) or the cooling provided to the equipment (cold aisle containment). Together with new monitoring and control systems, data center managers can optimise energy utilisation across the whole environment.
Types of Containment Systems
There are primarily two types of air containment systems: cold air containment and hot air containment. Both types of containment system offer advantages over the standard Hot Aisle/ Cold Aisle (HA/CA) configuration. Containment systems work in both raised floor and slab cooling environments.
Cold Aisle Containment (CAC)
Cold Aisle Containment (CAC) provides a physical separation between the cold air and the hot exhaust air by enclosing the cold aisle. A CAC system such as Panduit’s Net-Contain Cold Aisle Containment System facilitates the supply of cool air to equipment air intakes at a uniform temperature. It offers a focused cooling approach where the equipment air intake air temperatures are close to the supply air temperature. However, it also generates a high room ambient temperature, exposing workers to higher room temperatures.
Hot Aisle Containment (HAC)
Hot Aisle Containment (HAC) provides a physical separation between the cold air and the hot exhaust air by enclosing the hot aisle. The goal of a HAC system is to capture all of the cabinet exhaust air and return it to the cooling units. The rest of the room outside the HAC becomes a cold room with ambient air temperature close to the supply air temperature.
Vertical Exhaust Duct (VED) Chimney Cabinets
The primary goal of a VED system is to contain cabinet exhaust air and prevent mixing of cold and hot air streams in the data center room. The VED system captures and channels the cabinet exhaust air to a drop ceiling plenum. This approach requires addition of a solid rear door and the exhaust duct for each cabinet that connects to a drop plenum or opens up high above the cabinet. This technique allows the room ambient temperature to be maintained close to the supply air temperature.
Similar to HAC system, VED system also results in a room ambient air temperature close to the supply air temperature. However, the VED offers a cooler environment for anyone working in the hot aisle when compared to the HAC system.
A containment system reduces the overall cooling energy cost by preventing or reducing the mixing of cold and hot air streams, and stops leakage contamination. It also offers a significant opportunity for cooling energy savings regardless of its type or the type of cooling system used. This is due to the increase in allowable supply air temperature and an increase in return air temperature. The progressively higher supply air temperature and return air temperatures that can be achieved by using a CAC system and then a VED system, and ultimately a 100% contained version of either, leads to increased savings.