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Achieving an Affordable Green Data Center

3 Mar, 2011 By: Eric Austin, NER Data Corp. imageSource

Achieving an Affordable Green Data Center

Now that the economy is starting to show signs of life, 2011 is looking to be
a breakthrough year for many in the IT segment. Companies long held hostage by
poor cash flow and tight budgets, are finally planning to address overdue
equipment refreshes, facility upgrades, and even data center expansions. While
everyone cheers the changing momentum, many managers remain uncertain about
implementing projects that meet IT requirements and achieve corporate ‘greening’

But what does it really mean to green your data center? Some say
sustainability, others say reducing resources, yet while each concept presents
some level of validity, I would argue it’s really about reducing your carbon
footprint. Approaching the green data center concept by focusing on the carbon
footprint is more encompassing than other definitions, is achievable, and less
expensive than you might expect. 

The Green Grid, a global consortium dedicated to advancing energy efficiency
in data centers, created a metric for calculating the Carbon Usage Efficiency
(CUE).  Without losing you in technical specifics, CUE is a calculation of total
CO2 emissions caused by the total data center energy divided by IT equipment
energy.  There are different factors that go into this metric, but CUE is
designed to correlate energy consumption with resulting carbon emissions caused
by generating the energy.

At this point, you may be thinking about the virtualization project or
high-efficiency servers your organization just installed and be ready to pat
yourself on the back.  Don’t be too quick.  Would it surprise you to learn that
IT rack density has increased almost 23% during the past three years to 7.4kW
per rack? This means that while the equipment may be more efficient, more
equipment is being commissioned to handle growing computing capacities and
escalating data storage requirements.  Accepting that this growth cannot be
easily reversed, managers should address the supporting infrastructure to negate
the increasing power consumption. If your Data Center is like most others,
cooling accounts for roughly 40% of your power consumption bill each month, and
increasing the effectiveness of your cooling system should be, if easy and
inexpensive, a priority.

Cost Effective Measures

Improving the CUE of your data center can be easy and inexpensive. In fact,
there are several very simple, cost effective measures that can be taken to
reduce power consumption & in effect reduce carbon emissions. The following
suggestions are a simple roadmap to improving efficiency, lowering energy
consumption, resulting in a smaller carbon footprint. 

First would be to review the thermal containment system in your facility.
Creating an effective barrier between cold air supply and hot exhaust mixture
(bypass air) will improve the IT between computer room air conditioner intake
temperatures and outflow temperatures. Measures can range from basic blanking
panels and floor grommets to fully integrated containment systems but don’t
underestimate the simple fixes.  Assuming 1 CFM of bypass air @ 20ºF delta-T and
each rack unit equaling 64 CFM, costs for each open rack space (RU) can exceed
$355 per year. Multiply that by number of open RU’s in your facility and the
wasted energy is mind boggling.

Once all the holes are plugged and gaps filled, optimize your air delivery
system.  Traditional IT facilities often utilize a raise floor plenum system for
cool air dispersal. A problem common to this design is pressure irregularities
caused by impediments like large bundles of cable whips, raceways, piping, old
walls and changes in floor height.  With limited effort and little cost, your
air delivery system can be maximized by installing a sub-floor baffle system.
The baffles attach to the subfloor creating a channel through which you can
route cool air directly to the equipment or aisle that needs it. 

Thermal separation in a data center can be taken a step further by installing
a fully integrated containment system.  While it sounds overwhelming and
expensive, the concept is straightforward (separate hot air from cool air) and
the costs are often lessened by Utility rebates making the ROI only 12-18
months.  One case study for a rack site in California created an annual savings
over $500,000, reduced energy consumption by 181,000 kWh and paid for itself in
just nine months.  Savings like this not only impacts the bottom line but also
makes a dramatic impact on the CUE of the facility.

CUE can be further improved by creating a system that adjusts to the dynamic
energy requirements inside the facility. The growth of blade servers and high
density racks has a tendency to create hot spots.  In the past, data center
managers coped with hot spots by over-cooling the entire IT environment.  Today,
new technologies allow facility managers to control the airflow to and from
these specific areas without having to adjust the thermostat. Better yet,
solutions like pressure-managed chimneys and thermostatic air-movers adjust the
changes in pressure or temperature – which means they only operate as needed. 
This increased level of intelligence translates to energy optimization and is
the next step in greening your IT environment.

Impacting the Environment

Each of these steps in data center improvements has an impact on the
environment.  According to US Department of Energy reports, IT facilities waste
over 10 billion kWh per year. The carbon footprint of this wasted energy equates
to 5,883,000 metric tons of CO2. To put that in perspective, the average
American’s carbon foot print is 18.9 metric tons per year. In your efforts to
improve CUE, consideration should be given to the single largest energy hog in
the room – the air conditioning unit. 

Computer Room Air Conditioning (CRAC) units are a necessity for just about
any data center as they support the mission critical infrastructure by which
nearly all our business operations function. It’s also the one piece of
infrastructure where you can dramatically improve your bottom line all while
improving your carbon utilization effectiveness.  Important advancements in
straight-thru core designs, airfoil blowers and smooth-design housing, not found
in standard CRAC units, are being utilized in the next generation of air
conditioning units. This new engineered design is ultra-efficient, consuming
nearly 60% less energy than comparable models available on the market today. 
This efficiency gain, based on a case study comparing 30 ton CRAC units, equates
to a 29.4 metric ton reduction in CO2 emissions.

Today’s IT professionals need to balance their fiscal and social
responsibilities. In the past, unifying these objectives was never considered.
As new technologies evolve and allow us to balance those needs, achieving a
green data center is no longer an unattainable goal. 

Eric Austin is the Product Manager for the Technology Solutions Division
of NER Data Corporation. NER is an innovative leader in the demanding Data
Center Infrastructure Solutions and Managed Print business. What distinguishes
NER is that they have been a trusted advisor to IT for over forty years. Learn
more at www.nerdata.com.

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