40 / 80
conditions, they can provide full
economizer operation to reduce
compressor energy consumption to
zero. This system eliminates water use
and the need to introduce outside air
directly into the data center. It also
cuts the maintenance costs
associated with dampers or louvers
and water treatment for most
economization systems.
The energy-saving benefits of
economization also extend to chillers.
Relying strictly on outside air, or using
free cooling in concert with other
technologies for heat removal,
dramatically reduces chiller energy
consumption and, in some cases,
water usage.
SAVINGS FROM
IMPROVING
THE LEGACY THERMAL
MANAGEMENT
SYSTEM ADD UP
Taking advantage of the
aforementioned thermal management
opportunities in a legacy data center
can make a significant difference in
the energy bill, as shown in the
example below.
Assume a legacy data center
operating under the following
parameters:
• 5,000 square-foot data center
• Direct expansion (DX) thermal
management system with 500kW
capacity
• Precision cooling in hot-aisle/cold-
aisle arrangement
• 75° F return air temperature
• $0.10/kWh energy cost
GET A HANDLE ON NEW
CUSTOM AIR HANDLING
TECHNOLOGIES
Typical standard rooftop air handling
units are simply unable to maintain
the precise temperature and humidity
control demanded by mission-critical
environments. However, custom air
handlers are now on the market that
have been designed specifically for
large data centers using evaporative,
chilled water or DX technologies.
Air handling units designed for the
data center can offer a level of
customization and flexibility needed
in these unique environments and are
typically used in data centers from 5-
30 MW or higher. The units usually
feature intelligent controls that
provide advanced protection and
enable air flow, temperature and
economizer function to be adjusted
automatically based on IT load and
ambient conditions. With these
control systems in place, the units can
work more efficiently and help data
center managers achieve annual
mechanical PUE under 1.2. As with
traditional data center thermal
management, advanced controls are
critical to successful operation. Many
of these systems can also be simply
integrated with building management
systems and DCIM solutions.
REDUCE PUE USING FREE
COOLING CHILLERS
As with custom air handling units, a
new generation of air-cooled chillers
has been designed specifically for
data centers and mission-critical
applications. These chillers use built-
in economizers, system optimization
software and state-of-the-art
components—for instance, advanced
controls, digital scroll compressors,
EC fans, microchannel condensers
and electronic expansion valves—to
deliver high efficiency (mechanical
PUE as low as 1.08) and high
availability.
Free cooling chillers contain built-in
redundancy, fast restart capability and
continuous cooling availability in case
of water shortages, extreme ambient
temperatures and unstable power
supplies. Free cooling chillers come in
units up to 400 tons in capacity and
are ideal for chilled water data
centers up to 6 MW.
POWER
INFRASTRUCTURE
If your data center runs on a legacy
power infrastructure, its weaknesses
likely are its high operating cost and
inflexibility. Newer power
technologies are designed to
eliminate these deficiencies and
provide substantial benefits,
including:
• Up to 25 percent end-to-end
efficiency improvements
40
7X24 MAGAZINE SPRING 2015
Annual Energy Cost
% Energy Savings
Annual Energy Savings $
$190,000
NA
NA
$133,000 -$123,500
30-35%
$57,000 - $66,500
$85,500 - $66,500
55-65%
$104,500 - $123,500
THE ANNUAL ENERGY BILL FOR THIS DATA CENTER IS $190,000, WHICH CAN BE CUT SUBSTANTIALLY:
Legacy system without improvements
First, add containment and increase
return air temperature 10° F. Then add
advanced controls to optimize airflow
and cooling capacity
Upgrade to New DX Technology with
Pumped Refrigerant Economization