Top 5 Ways to Make your Datacenter Efficient

Top 5 Ways to Make Your
Data Center Efficient
The Brands You Trust.
^
Business-wise, Future-drivenTM

Data Centers
Schneider Electric Table of Contents
Top 5 Ways to Make Your Data Center Efficient
Table of Contents
Introduction..................................................................3
Metering & Monitoring................................................13
Conclusion.................................................................14
1. Right-sizing.............................................................4
2. Close-coupled cooling.............................................6
3. Free cooling.............................................................7
4. Containment aka Airflow Management......................9
5. High Voltage Distribution........................................11

Schneider Electric 3
Data Centers
Introduction
With the litany of material on energy efficiency in
the data center, do you know - bottom line - what
will have the greatest impact?
The purpose of this ebook is to discuss, in order of impact, the top
five energy saving practices in new and existing data centers.
If we were designing “the perfect data center”, these are the 5
efficiency characteristics would we be sure to incorporate. If you
have an existing data center, don’t worry; you can still implement
these practices now, on your next refresh, or on your next
expansion.

Data Centers
1. Right-sizing
Overview
Starting at the top of our list is right-sizing – by far, the most cost-
impacting aspect of data center design. Here’s the idea: data centers
and network rooms are routinely oversized to estimated long-term
capacity requirements. In some cases, this is more than twice their
required capacity. Over-sizing drives unnecessary capital,
maintenance, and energy expenses, which are a substantial fraction
of the overall lifecycle cost. Most of this excess cost can be avoided
by using modular architecture that can quickly and cost-effectively
adapt to changing requirements and still deliver high availability.
To qualify the benefits of
right-sizing, check out our
Data Center Design Planning
Tool. With this tool you can play
with various scenarios to see the
potential savings in capital cost,
energy, and maintenance. If you
want to learn more about growth
planning and the value of right-
sizing, take a look at the complete
white paper, Data Center Projects:
Growth Model

Data Centers
Details
The physical and power infrastructure of data centers and network rooms is
typically oversized by more than 100%. This unused capacity is the single
largest avoidable capital cost, and also creates needless operating and
maintenance costs. What’s the solution? A modular infrastructure design
that scales or phases with the IT infrastructure. Here are the benefits:
• The one-time engineering would be reduced
• The infrastructure would be provided in pre-engineered modular
building blocks
• The components could be “plug and play” without the need for hot work
• Special site preparation such as raised floors would be reduced
• The system would be capable of operating in N, N+1, or 2N
configurations without modification
• Installation work such as wiring, drilling, cutting would be greatly
reduced
• Special permitting or regulatory procedures would not be required in
order to increase capacity
• The equipment cost of the modular power system would be the same or
less than a traditional system
• The maintenance cost of the modular power system would be the same
or less than the cost of the traditional centralized system
Right-sizing

Data Centers
2. Close-coupled cooling
Overview
The second most effective way to lower PUE is through close-coupled coolng.
Close-coupled or row-based cooling brings the cold source closer to the heat
source: the rack. By placing the cooling equipment in the row, the heat is
captured and neutralized before mixing in the room. The primary gains here are
through (1) better airflow management and (2) lower fan speeds required to push
cold air to the racks and pull hot air back into the plenum.
Details
In a typical data center set up, computer room air handlers (CRAHs) are placed
around the room, directing cold air up through a raised floor. As rack power
density grows beyond 5kW, challenges with air delivery and heat removal with
perimeter CRAHs/CRACs become evident. Distance between the cooling units
and the heat load make it difficult to properly remove the heat generated from
IT equipment without mixing with supply air. This separation results in hot spots
and a complicated design approach to air distribution. To add to this problem,
the airflow demands of the IT equipment also increase with power density.
To address the separation of cooling units and heat loads, row-based designs
place the air-conditioning units in the row of rack enclosures. Incorporating a
hot/cold aisle design, heat is removed from the hot aisle as it is expelled from the
IT equipment. This brings cool air right to where the heat is generated and elimi-
nates hot air from mixing with ambient air (aka, in-row or close-coupled cooling).
This increases cooling predictability and efficiency, which saves you money on
electrical costs. By closely coupling the cooling with the heat load, you prevent
exhaust air from flowing back to sensitive IT equipment. This ensures that
equipment temperatures are constantly held to set point conditions.
Close-coupled
cooling +
containment
Close coupled cool-
ing prevents much of
the hot/cold air mix-
ing that occurs when
a perimeter unit sits
at a distance from
the IT equipment it
is supposed to cool.
Containment can be
used with either row
or perimeter units,
but it is more neces-
sary for perimeter
units because of
their inherent inef-
ficiencies in distrib-
uting air. Perimeter
units have another
disadvantage in that
their fans generally
operate at a fixed
speed, so they don’t
adapt to varying IT
loads, which wastes
significant energy.
>
Want more detail?
Here’s the full white
paper: Energy Efficient
Cooling for Data Centers:
A Close-Coupled Row
Solution

Data Centers
3. Free cooling (economizer mode)
Overview
Ranking third on our list is the use of free cooling (aka operating in economizer
mode). Operating in economizer mode saves energy (and money) by using
outdoor air during colder months of the year, allowing refrigerant-based
cooling components, like chillers and compressors, to be shut off or operated
at a reduced capacity. In certain climates, some cooling systems can
save over 70% in annual cooling energy costs, corresponding to over
15% reduction in annualized PUE – very attractive benefits.
Details
Historically, building an economizer mode into a data center cooling system
entailed extra cost and complexity, and was only justified in situations with
extremely favorable weather conditions, such as high latitudes. However, this
has changed and economizer modes are now considered advantageous in
almost all locations.
For detailed
information on the
different economizer
modes read Economizer
Modes of Data Center
Cooling Systems

Data Centers
Without detailing the 17 types of economizer modes, it’s important to
clarify that “free cooling” is not entirely free. When a cooling system is
in economizer mode, a significant amount of energy is saved in one
part of the cooling process, but it doesn’t eliminate cooling costs
altogether. This distinction is important because it’s one of the reasons
all economizer modes are not created equal. All economizers bypass
the compressor function either partially or fully, but how they do it (and
the benefits of each) are different. Ultimately, 6 of the 17 are most
beneficial to data centers. Here is a broad level comparison:
Did you know...
Free cooling (economizer mode)
Quantitative com-
parison between
types of economizer
modes.
Whichever economizer
mode you choose, it
makes little sense to
invest in one without
first investing in a
containment system,
which leads us to the
fourth most important
efficiency best
practice…
>

Data Centers4. Containment, aka Airflow Management
Overview
Up fourth in our best practices is containment. The idea is simple: separate
the hot air from servers and the cold air from computer room air conditioners
(CRACs), and energy efficiency improves significantly. You can contain either
the hot air (hot aisle containment system, or HACS) or the cold air (cold aisle
containment system, or CACS). Both options have pros and cons, but hot
aisle containment tends to have higher efficiency gains. This Google video
provides a good explanation of containment and shares some low-cost
solutions.
Details
While the idea of containment is straightforward, most existing data centers
do not manage their airflow. Aisle containment – whether hot or cold - creates
a higher temperature differential between air entering and leaving CRAC units,
which improves their efficiency. Other benefits of containment include elimina-
tion of hot spots, more uniform and potentially higher server inlet temperatures,
and the related increase of potential “free cooling” hours in units equipped with
economizer modes.
Cold Aisle containment
But here the simi-
larities end, as the
two approaches
differ substantially
in their impact on
the temperature in
the work environ-
ment, PUE, and
number of econo-
mizer mode hours.
Hot Aisle containment
>

Data Centers
The choice of hot aisle containment over cold-aisle containment can
save 43% in annual cooling system energy cost, corresponding to a
15% reduction in annualized PUE. Here are the major considerations for
both:
• Cold aisle containment, though less efficient than hot aisle, may be
a more viable option for existing data centers with standard
raised-floor cooling.
• Hot aisle containment is best for new builds or very large data
custom-built building to efficiently handle the large air volume.
However, it is significantly more efficient than cold aisle containment.
Hot aisle containment is excellent for large, purpose-built data
centers because of the efficiency gains through economizer modes.
• There are employee work environment considerations to keep in
mind for both containment systems – CACS can produce very hot
working areas that may not meet OSHA regulations for employees
permanently stationed in the room. You may also need to make
special considerations for equipment in the room, such as tape
racks or storage that are not part of the contained cooling system.
Did you know...
Containment, aka Airflow Management
Read more in the
full white paper:
Impact of Hot and Cold
Aisle Containment on
Data Center Temperature
and Efficiency

Data Centers
5. High Voltage Distribution
Overview
Last on our list of top five efficiency best practices is high voltage distribution.
If you minimize the number of times electricity is transformed between the
electrical grid and the equipment it powers, you will avoid the energy losses
that take place in the transformers. Take this a step further by running higher
voltages (240V) to IT equipment – as the rest of the world does – and your
equipment will run at maximum efficiency.
Details
Did you know that most existing data centers use the same power distribution
architecture that was developed about 40 years ago? Not only is that ancient
in technology terms, it’s also not what most data centers around the globe
use today. This 40-year-old power architecture limits the scalability, efficiency,
configurability, manageability and power density in the data center – on two
counts:
1. IT equipment doesn’t operate at maximum efficiency at lower volt age
levels.
2. In a typical power distribution set up, voltage is stepped down
several times before actually reaching the equipment, and with
each transformation, there are energy losses. By switching to
higher voltage distribution, you minimize step-downs and their
associated wasted energy.
Want to read the
full white paper?
Click here: High-Efficiency
AC Power Distribution for
Data Centers

Data Centers
By using a 240V distribution system instead of the traditional 120V
system, you can save 25% in material cost and 10 year energy
cost, and save floor space and weight loading. This alternative
design can operate alongside conventional power distribution designs
in existing data centers. The illustration on this page provides a one-
line diagram of traditional distribution vs. high voltage distribution.
Traditional Distibution
The traditional power distribution system for large data centers in North
America is a 480/277 three-phase power system supplying power
distribution units (PDUs) which convert the voltage to the 208V and
120V single-phase branch circuits used by the IT equipment. The PDUs
contain oversized, heavy isolation transformers which increases energy
costs and consume valuable floor space.
The proposed 240V power distribution system is an adaptation of the power dis-
tribution system used in the rest of the world. Increasing the voltage to 240V (the
highest voltage supported by most IT equipment) makes it practical to consolidate
the PDU transformers into a single isolation transformer on the bypass of the UPS
and then use auto-transformers to step down to 240 volts. Sizing a single trans-
former to the UPS capacity reduces PDU transformer over-sizing, saving significant
energy. In addition, this transformer can be located outside the data center IT
space, which removes a significant amount of weight and IT floor space. This de-
sign also increases the power density capability per rack without adding extra circuit
breakers as would be the case with the 120/208V design.
High Voltage Distribution
Did you know...
High Voltage Distribution

Data Centers
Metering & Monitoring
Now that you know which 5 efficiency practices will have the greatest impact
on your bottom line, an important component of continually improving
efficiency is metering and monitoring performance. You can’t control what
you don’t measure. If you don’t know what is functioning inefficiently and
exactly how inefficiently, you can’t make sound decisions to improve
efficiency. So, the first step towards efficiency is metering and monitoring
energy usage in your data center.
Details
To improve energy efficiency in your data center, you need data about your
facility’s performance, you have to know how to evaluate it, and then you have
to know how to compare or benchmark your performance to other, similar data
centers. With metrics like power usage effectiveness (PUE) gaining mainstream
usage, most of the industry agrees that you must measure efficiency to estab-
lish a baseline. However, these measurements are meaningful only when used
in conjunction with models; an effective metering/monitoring system is able to
diagnose the sources of inefficiency and suggest corrective action. The anal-
ogy below with automobile fuel economy is helpful in understanding the types of
information we need in order to interpret data center efficiency data.
To manage efficiency,
you have the option
of permanently instru-
menting the appropri-
ate power flows for
real-time efficiency
metering, or you can
perform periodic
audits of power
flows using portable
instruments. For new
data centers, perma-
nent instrumentation
makes sense. For
existing data centers,
we recommend a mix
of limited permanent
instrumentation and
periodic audits.
> Want to know
exactly what to
measure and how to do
it? Learn how in the full
white paper, Electrical
Efficiency Measurement
for Data Centers

Data Centers
Conclusion
These five tips, more than any others, will help you
improve energy efficiency and dramatically lower
capital and operating costs for years to come.
If you aren’t sure where to start, consider an energy efficiency audit. It
will draw a roadmap for planning your new data center or to optimize
an existing one.
For more tips on improving energy efficiency and lowering total cost of
ownership in your data center, be sure to read the white papers previ-
ously referenced:
• Electrical Efficiency Measurement for Data Centers
• Data Center Projects: Growth Model
• Energy Efficient Cooling for Data Centers: A Close-Coupled
Row Solution
• Impact of Hot and Cold Aisle Containment on Data Center
Temperature and Efficiency
• High-Efficiency AC Power Distribution for Data Centers

Data Centers
132 Fairgrounds Rd. - West Kingston, RI 02892 - 800-800-4272 - www.schneider-electric.com
Theglobalspecialistin
energymanagement™

Top 5 Ways to Make your Datacenter Efficient

Recomendados

Recomendados

Mais conteúdo relacionado

Destaque

Destaque (6)

Último

Último (20)

Top 5 Ways to Make your Datacenter Efficient