AISLE CONTAINMENT
By Keith Stewart, Product
Marketing Manager, Networks
Centre
www.networkscentre.com
Rising energy costs, and the desire to optimise
reliability and efficiency have focused minds on
cooling in data centres
Data centre cooling and power efficiency is a vast topic with
the pros and cons of different methods continually being
debated as chiller and data centre infrastructure monitoring
(DCIM) technology evolves.
One principle that’s universally accepted is that preventing
the mixing of hot (exhaust) and cold (inlet) air in any form
of data room is highly desirable, and a key part of cooling
strategies in data centres. Indeed, it’s essential in data centres
aiming to achieve high reliability and minimal energy costs or
power utilisation effectiveness (PUE).
The construction design of the building fabric, and means
of supplying chilled air will both have a large influence on the
method used to prevent hot and cold air mixing. New data
centre facilities may have the latest free air adiabatic chillers
or advanced water cooled chillers, but they still need to ensure
segregation of hot and cold air in the same way that the
more traditional cooling via edge computer room air handling
(CRAH) units do.
A common dilemma facing modern data centres: how best
to combat the ever-present problem of data centre cooling
in a dynamically changing environment, in order t o achieve
maximum efficiency with minimal disruption. The most well
established, popular and cost-effective choice for data centre
cooling is cold aisle containment systems (CACS); however,
studies have shown that hot aisle containment systems
(HACS) are more efficient. So why aren’t HACS the most
popular choice? Let’s remind ourselves what CACS and HACS
are, and how they work.
Cold aisle containment
Cold aisle containment systems are one of the most widely
recognised data centre cooling solutions. By managing airflow
CACS restrict the loss of cold air, and prevent the mixing of
cold and hot air. They’re designed for server and network
cabinets, and other computing equipment in data centres,
server rooms, or office environments primarily to increase
energy efficiency.
Aisle containment is set-up by lining up server and network
cabinets in alternating rows, with cold air intakes and hot air
exhausts facing opposite directions. The rows in which cold air
flows are called cold aisles, and the rows in which hot air flows
31
are called hot aisles. A containment system is used to isolate
hot and cold aisles from each other to prevent hot and cold
air from mixing, thus forming a pod.
Hot aisle containment
Hot aisle containment has gained increasing popularity as
denser computing and power loads have evolved – through
blade servers, for example. The hot aisle ensures that hot
exhaust air from the racks is contained within the aisle,
enabling the rest of the data centre to become a large
reservoir of cold air. It’s similar to CACS, in that the racks are
www.networkseuropemagazine.com