Overcooling of data centers is a perennial problem for the industry, but eCool Solutions says it has a low tech fix that offers a new approach to solving the problem.

The company says that by improving air management in legacy data centers through its cold aisle containment product, energy consumption is cut by over 15% which can rise to 30% when combined with free cooling.

Yahoo! was among the first data center owner that trialed the product and became the first to install it.

Niall McEntagart, European data center operations manager at Yahoo, said: "The solution is not particularly high tech - it's very cheap and is easy to install, it suits a legacy data center environment and is cost effective. The results are pretty good in terms of cooling efficiencies and we are looking to do something very similar in other locations.”

The containment solution involves enclosing the racks and/or aisles with plastic attached to a frame.

Dataracks founder Jeremy Hartley developed Ecool Solutions. He says the solution is targeted squarely at the legacy data center market and he names Unilever, and Level 3 as trialing and deploying the system.

Unilever is undergoing a six month trial and Level 3 is rolling out the system to all of its European facilities, said Hartley.

Managing Fire Risk

One of the potential problems, and one that had to be resolved with Yahoo! and its landlord Level 3, was an insurance issue.

Many legacy data centers have water sprinklers for fire suppression and sealing the aisle off with a roof raised concerns with the insurance company.

McEntagart said: “The only slight issue is if you are using water based fire extinguishers you need to ensure you are complying with the terms of your insurance. If you have gas based fire extinguishing then it is not an issue.

The solution was simple.

“We’ve tackled issues as they’ve come along. We solved this problem by designing the roof to melt at 58 degrees, which is 20 degrees below the temperature at which the spinklers activate,” said Hartley.

Another effect of the containment is that by preventing hot air mixing the facility will keep cool for an extended period after an outage, providing valuable extra time to allow for it to be rectified.

“It is another advantage that if there is a cooling outage it can give you a significant time advantage before you start seeing cooling alerts," said McEntagart.

Data Center Legacy

Data centers have evolved over time said Hartley and can contain a diverse range of cabinets, and as a result conditions can vary both along and between the aisles. By using thermal imaging, measuring temperature and humidity, and monitoring the flow of air within the aisles, Hartley and his team were able to identify the common problems which included: hot stagnant air, excessively high and low temperatures, mixing of hot and cold air, poor air balancing and flow and considerable by-pass air.

“It was not uncommon to see a 40° variation in temperature between cold and hot aisles and as a result the entire building was usually overcooled to ensure that the temperatures remained low. The cold aisle was often well below 20°C – the acceptable level. Our solution was to improve the airflow management to ensure a controlled flow of cooled air through the servers, creating optimum conditions for the internal fans. With the cooling systems working more efficiently, and greater consistency in the aisle temperature, it is possible to reduce the amount of air conditioning required. Not only does this dramatically cut energy consumption but it also reduces the need for humidifiers which are used to help prevent static build-up,” said Hartley.

McEntegart said: “When eCool was installed we noticed the difference within an hour. The temperature variations reduced and the cold aisle temperatures have kept consistent within 2-3°C. This has enabled us to balance the cooling system, remove two of the eleven chillers and cut cooling energy consumption by 15%.”

The eCool Solutions service includes the pre-implementation monitoring and thermal imaging to identify hot spots and circulation issues.

"We go along with a thermal imaging camera, take images of hot and cold isle, look at leakage and other issues. With Yahoo! we did a stage, fit blanking panels, measured it, put a roof on, measured it,” said Hartley.

McEntegart said: "As a company we are committed to reducing our environmental impacts. By encouraging the development of approaches such as offered by eCool Solutions we have shown that it is possible for the industry to significantly reduce its carbon footprint.

65kw per hour saving on a 820kw supply is equivalent to 298 tonnes of carbon dioxide per year (in a 870 m2 facility) and £35k in power charges. It provided payback in direct costs in three months for Yahoo!

No Mystery

"A data center operates 24/7 and as any minor outage would create huge consequences for the end clients. We have built considerable redundancy into our facility. This includes a spare CRAC unit for every two in operation and keeping the temperature lower than required to allow for variations,” said McEntagart.

Among other benefits, said eCool was an improvement in the mean time between failure of server hard drives. “Some companies are going through bucket loads of servers,” said Hartley.

Hartley likes to be adaptable. He says: “If you don’t like plastic curtains, we can do doors with self contained bearings and wheels, we can give you sealed doors with electronic locks. It is a utilitarian solution, it is adaptable to different racks. We’ve made it as low tech as possible. There is no mystery to it.”