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Keeping IT cool

MARKET FEATURE

DATA CENTRES

As data centres try to keep pace with rapidly changing usage patterns, so do their cooling techniques. Industry experts share insights and updates on best practices and technologies.

By Rajiv Pillai | Features Writer

To state the importance of data centres in the present day of quick connectivity and information

dissemination is to state the obvious. As data centres try to keep pace with rapidly changing usage patterns, so do their cooling techniques. Pierre Havenga, Managing Director at Emerson Network Power for the Middle East and Africa region, gives an interesting analysis: “If we look at the telecom industry, a

few years ago, approximately 90% was voice-centric and 10% was data-centric. Now, it’s approximately 70% data-centric and 30% voice-centric. This is mainly driven by applications on smartphones and people are spending more time downloading apps or text messaging, creating demand for storage of data. You don’t record all the voice communications between people on cell phones, but you need to record all the data. And that’s what’s driving

the need for data centres.” In light of this, maintaining and cooling data centres has gained primacy.

A whitepaper by Emerson Network Power, a business of Emerson, reveals that cooling systems – comprising cooling and air movement equipment – account for 38% of energy consumption in data centres.1 As Havenga puts it simply, “You have to reject heat from the data centre; servers generate heat and heat has to be rejected.”

Don’t lose your coolCooling failure is not an option for data centres. In Havenga’s view, the loss of revenue could amount to millions of dollars per day if a data centre is unavailable, with the losses being different for different industries. “For example, for the telecom industry, the losses are quite huge,” he says. However, that could be the least of the problems. As Bart Holsters,

A temporary failure of an airport data centre is certainly much more critical than the temporary failure of Twitter’s data centre, though some may argue that

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Operations Manager at Cofely Besix Facility Management, points out, a cooling failure will result in loss of uptime, with the servers eventually shutting down and the electronic equipment getting damaged.

Mohammad Abusaa, a Business and Project Development Professional with HH Angus and Associates, and a veteran when it comes to data centre cooling, presenting a clear picture of the stakes involved in case of cooling failure in various sectors, says: “The critical nature of cooling for a data centre can be understood from the fact that in many cases, losing cooling for less than five minutes could cause the IT equipment to fail. In some high-density applications, the time could be less than two minutes. The criticality of IT systems’ failure is gauged by the function of the data centre. In other words, a temporary failure of an airport

data centre is certainly much more critical than the temporary failure of Twitter’s data centre, though some may argue that.” The reason for such cooling failure, he says, can directly be related to the cooling system itself, such as the failure of pumps, fans or chillers, and, at times, indirectly related to the cooling system, such as power outages.

Abusaa elaborates that when failure occurs in the cooling system, standby equipment or paths are brought online to ensure continuous supply of cooling to the IT space. Therefore, attributes like redundancy and standby should be factored in at the design stage of cooling systems. When failure occurs in the power supply, an Uninterruptible Power Supply (UPS) device connected to the critical parts of a cooling system – usually the distribution components – will maintain the operation of the cooling distribution network, while the backup generators come online, thereby providing sufficient power to bring the

cooling generation system back online within minutes of losing power. In Abusaa’s view, this is the usual contingency procedure in case of a cooling failure.

Cooling solutionsSince cooling is an imperative for data centres, ASHRAE has defined standards for their cooling requirements, which normally dictates the operating conditions.

Håkan Lenjesson, Market Area Director at Systemair for the Middle East and Turkey region, says that ASHRAE has been broadening the operating ranges and also recommending a very low Power Usage Effectiveness (PUE). Havenga adds: “Today, ASHRAE’s recommended conditions range from 18 degrees C to 27 degrees C. However, the allowable range can even go up to 35-40 degrees C, depending on the server technology.”

With the ranges and requirements defined, the next step is to decide on a cooling solution, as there are several

options available in the market. Havenga says that most data centres currently adopt the traditional direct expansion technology, which is applicable everywhere in the world. “Then there is free cooling, where you have fresh air coming directly from outside,” he points out, and adds, “Or indirect cooling, where you are cooling a medium, typically water. Even further, there are adiabatic solutions, which are an enhancement of the cooling capacity of the chiller. It increases the free cooling capacity.”

Havenga reveals that the latest technology in the market is evaporative free cooling. “This is a way of cooling a data centre without using a compressor; so basically, all-year-round cooling,” he says. He believes that the main driver behind this is energy savings, adding that energy is the single biggest cost incurred by a data centre, which has led to various advancements in technology, InRow cooling being one of

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Bart Holsters

Pierre Havenga

Mohammad Abusaa

Håkan Lenjesson

Figure 1

DATA CENTRES

MARKET FEATURE

October 201546

Håkan Lenjesson says

that most organisations

continue to plan and

design new computing facilities

without much change or

innovation. For example, first,

they design a building and leave

some portion for the data hall

or whitespace. Then, they fill the

whitespace with as many server

racks as possible. In Lenjesson’s

opinion, designing data centres

in the traditional manner can

create a wide range of problems.

He explains, “For example,

an undersized or oversized power and cooling

infrastructure can limit operating capacity or

increase capital expenses.”

He believes that large corporations are looking

for some extra free cooling, while keeping the

PUE as low as possible.

“Companies like Google, Facebook, etc., are

building their new data centres in the very

A walk through Emerson Network

Power’s Customer Experience Centre,

Dubai, will make you realise that

data centre cooling is a serious business.

Climate Control Middle East visited the

facility where Pierre Havenga demonstrated

that cooling in data centres was more

about managing the heat rather than

cooling. He explained: “Five years ago, you

allowed a certain amount of cool air into

your data centre, irrespective of whether

it was required or not. Nowadays, with

Electronically Commutated (EC) fans,

software and wireless monitoring, we can

manage the amount of cool air based on

what is required by the data centre. So, you

don’t need to provide cool air if there is no

heat.

“So our other solution is that you can

even switch off servers. If the server fan is

running, then the fan consumes power, and

the power generates heat. So, it’s getting

to that level of managing your heat levels.

That’s why we call it Thermal Management.

We don’t call it cooling anymore, because

now you manage the thermal side of your

data centre. We manage the temperature

requirement from the rack back to the

chiller.”

Flying north

“We don’t call it cooling anymore”

them. Havenga explains that InRow cooling is a type of air conditioning system commonly used in data centres, in which the cooling unit is placed between the server cabinets in a row for providing cool air to the server equipment more effectively.

Abusaa puts in a nutshell a few of the current trending innovations in the market: “There is modularisation – the main drivers behind this are quality control, cost and delivery schedule. Then there is Direct Liquid Cooling, followed by a continuous development of IT hardware systems that run at higher temperatures and humidity levels and, finally, the on-site Combined Heat and Power (CHP) systems.”

Making the server serveAmidst these cooling options, there lie several challenges, with availability and uptime being the primary ones. “You have to make a redundant solution, no matter where you are in the world,” Havenga says. “This is required so that you will not lose production, because if you lose production, you will lose millions every day.”

Abusaa points out that cooling load or capacity management is one of the most critical challenges in designing a data centre cooling system.

north places of the planet,

for example, to north of

Sweden, Finland, Canada,

etc.,” he reveals. He elaborates:

“Instead of under- or over-

provisioning their new facility’s

power and cooling resources,

companies are installing the

optimal infrastructure for the

precise array of hardware and

enclosures they’ll be using.

Instead of improvising solutions

for efficiency-sapping structural

defects, they’re preventing

those defects from occurring in

the first place. The end-result

is a data centre that’s not only less costly

to cool and maintain but also more reliable

and better suited for business requirements.

They can also allow for significantly increased

intensity usage. ROI is a very important

factor, so doing it right from the beginning is

essential; this is where modular systems are

coming into place.”

A Technical Manager operating on Emerson Network Power’s

Liebert CRV Thermal Management Unit (© 2015 Emerson Electric Co)

Emerson Network Power’s Customer Experience Centre

For security and access reasons, the CRAC unit might need to be relocated

October 2015 47 www.dencohappel.com

GEA Middle East LLC

Technopark Head Quarters Building,

Block B, 3rd Floor, Office 321,

Technopark, P.O. Box 261236,

Dubai, United Arab Emirates

Scott Ross

Director of Sales

MENA & APAC

Mobile: +971 50 5548502

Office: +971 4 881 6065

Air Treatment Holding

becomes

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October 201548

“Hot Huts”

Google has designed custom cooling systems for

its server racks. The systems are called “Hot Huts”,

because they serve as temporary homes for the hot

air that leaves the servers – sealing it away from the

rest of the data centre floor. Fans on top of each Hot

Hut unit pull hot air from behind the servers through

water-cooled coils. The chilled air leaving the Hot Hut

returns to the ambient air in the data centre, where

the servers can draw the chilled air in, cool them down

and complete the cycle.

Evaporative cooling

As hot water from the data centre flows down the

towers through a material that speeds evaporation,

some of the water turns to vapour. A fan lifts this

vapour, removing the excess heat in the process, and

the tower sends the cooled water back into the data

centre.

Using seawater

Google’s facility in Hamina, Finland, uses seawater

to cool without chillers. The company has chosen

Hamina for its cold climate and its location on the

Gulf of Finland. The cooling system pumps cold water

from the sea to the facility, transfers heat from the

operations to the seawater through a heat exchanger,

and, then, cools this water before returning it to the

Gulf. Since this approach provides all the needed

cooling year round, Google claims to not have installed

any mechanical chillers.

How Google does it

He stresses that capacity management is related to the phasing of data centre construction, expansion or phasing out of IT loads within the data centre, variation in the cooling load profile within the day/month/year and variation in the cooling load requirements within the same data hall or even at the server rack level.

The other challenges are maintenance-related. Abusaa stresses that it is crucial to understand that a facility that is running 24/7 and has strict security access regulations will have its design and operation challenges when it comes to maintenance. He says, “For example, while having a Computer Room Air Conditioning Unit (CRAC) installed in a specific location is the most efficient solution, for security and access reasons, the CRAC unit might need to be relocated to ensure that the maintenance personnel do not have access to the IT equipment, as there might be a possibility of accidently damaging the IT equipment while maintaining the CRAC unit.”

And then, there is always the issue related to humidity (See Figure 1) and air quality. “Similar to hospitals and other

At Google data centres, the company often uses water instead of chillers, as an energy-efficient way

to cool…

(Information source: https://www.google.ae/about/datacenters/efficiency/internal/#water-and-cooling)

“IT, data centres and server

equipment consume electricity

and emit heat as a ‘waste

product’,” says Ziad Youssef, Vice

President of IT Business - UAE, Gulf

Countries at Schneider Electric. “At such

an enclosed environment with sensitive

technology, the heat can be damaging.”

As data centres experience exponential growth in the region,

he believes that new solutions to curtail the simultaneous rise

in energy costs will be essential. “One such solution is cooling

– which is critical to the smooth functioning of a data centre,

and to the maintenance of hardware carrying mission-critical

enterprise data,” he says.

Combating ‘waste’ heat

Ziad Youssef

Similar to hospitals and other critical facilities, maintaining control of the Indoor Air Quality to avoid contamination is crucial

critical facilities, maintaining control of the Indoor Air Quality to avoid contamination is crucial,” Abusaa reveals, and adds, “This is not only achieved through filtration but also through the design of data centres and operation and maintenance guidelines.” He is emphatic that filtration, dehumidification, access control and other practices should address the air-quality issue.

Reference1. http://www.emersonnetworkpower.com/documentation/en-us/brands/liebert/documents/white%20papers/enterprise-data-center_24622.pdf