Contrary to conventional wisdom, you may have more leeway with data centre air temperature and humidity than previously thought. New findings indicate that servers and storage equipment actually perform just as well at higher air temperatures and lower humidity. This is great news for companies bent on lowering energy costs and doing right by the environment. Data centre cooling is a major energy consumer, so allowing even slightly warmer temperatures can mean big savings, if you do it right.

Computers are power-intensive devices, meaning a great deal of electricity is required to power small equipment. An enterprise data centre may contain hundreds, if not thousands of pieces of IT equipment, all using lots of energy and therefore generating lots of extra heat.

The traditional approach to keeping data centres cool has been to apply brute force and cool the environment to meat-locker temperatures (another energy-intensive process).

However, these chilly standards aren’t necessary if good air management practices are in place. Bill Kosik, principal and green business technology lead at HP Critical Facilities Services, says that data centre equipment performs well and without failure at higher temperatures than previously thought.

'Based on new research data, industry organisations such as the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) have relaxed operating temperature and humidity requirements', says Kosik. 'This is very important from an energy use and environmental standpoint. Raising the air temperature from 60°F (16°C) to 70°F (21°C) could reduce energy use of the cooling systems by 20 percent'.

The real trick though, says Kosik, is in equalising the overall temperature of the data centre. That means identifying and eliminating hot spots and redistributing cool air more evenly by optimising use of your AC equipment.

Many data centres continually run air conditioning (AC) units at full capacity. On top of that, many also run back-up AC units full time, just in case.

'Most AC units running at full speed are blowing more air than is necessary', explains Kosik. 'Reducing the speed of your fans by 25 percent can reduce that unit’s energy consumption by up to 60 percent'.

According to Kosik, AC units running at full capacity should focus on areas that create the most heat. But you must also identify the cool spots that require less air flow and reduce fan speeds in those areas.

As an additional step, Kosik recommends, turn off your redundant AC units and let them do what they’re supposed to do - serve as back-up in case primary units fail or temperatures rise too high. But be sure to conduct thorough maintenance of AC equipment on a regular basis, and test control systems to verify that they’ll properly react to anticipated failure scenarios.

Humidity is the third culprit in the data centre power binge. Servers and storage equipment need just enough moisture in the air to prevent electrostatic discharge. Yet too much moisture causes erosion and can shorten the equipment’s lifespan. Maintaining this narrow, optimal range of humidity typically requires energy-sucking humidifiers.

However, similar to misperceptions about data centre air temperatures, an acceptable range of humidity may actually be broader, especially if overall air temperatures can increase.

'The standard humidity tolerance level for data centres was previously stated at 40 to 55 percent', says Kosik. 'But we’re seeing that most equipment can tolerate a wider range, more like 30 to 60 percent, depending on the temperature'. This means data centres don’t have to exert as much energy trying to maintain a narrow, optimal range of humidity.

As welcome as these new findings on temperature may be, Kosik also cites the need for further investigation. Kosik advises companies to proceed cautiously and to conduct thorough analysis before adopting new heat and humidity tolerance standards.

With the acquisition of EYP Mission Critical Facilities, HP filled an important niche in its data centre services portfolio and greatly expanded its expertise in energy efficiency. Now HP Critical Facilities Services offers a range of services to address data centre planning, design and operations issues.

To get started, you can take advantage of specialised services, including:

• Critical Facilities Consulting –lay the groundwork with assessment, modelling and facility consolidation and migration planning services.
• Critical Facilities Design –chart your course for success with solutions for financial planning, reliability, scalability and maintenance challenges.
• Critical Facilities Assurance –achieve your performance and operational goals with verification, validation and improvement services.

With a heritage of helping more than 500 companies on data centre energy efficiency projects, HP Critical Facilities Services has the experience to help bring your enterprise in from the cold.

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