CHICAGO – After years of slow but steady adoption, KyotoCooling technology has gained significant traction with data center service providers. Over the past year, the cooling solution has been integrated into new facility designs for Compass Datacenters and RagingWire Data Centers, as well as the new Chicago data center project for QTS Realty Trust.
KyotoCooling is an implementation of indirect air cooling, an approach to keeping servers and storage cool that has been growing in popularity within the data center industry.
Cooling has been a focal point in the drive to become more energy efficient, with many data center operators turning to free cooling – the use of fresh air to cool servers, instead of air conditioning systems employing power-hungry chillers. Free cooling saw its strongest early implementations at single-tenant hyperscale data centers from Google, Yahoo and Facebook, which could customize their systems around their own requirements.
In recent years, air cooling strategies have been adopted by multi-tenant data center service providers, who must balance the needs of customers with a broad range of IT equipment and power densities. A growing number of these providers are turning to KyotoCooling, citing its combination of efficiency and versatility.
Targeting Chillers and Power Bills
The Kyoto technique use a heat wheel, also known as a rotary heat exchanger. It’s a refinement of existing approaches that take advantage of outside air to improve cooling efficiency and reduce data center power bills. The heat wheel eliminates the need for chillers in most operating conditions, but offers advantages over direct fresh air cooling, eliminating risk from contamination and humidity.
As the wheel spins between two compartments, the ambient air cools the wheel, and then the wheel cools the supply air for the data center. The two airflows never meet or mix. The system can work without water, which reduces a data center’s impact on the local utility infrastructure.
A diagram of a cooling system using a Kyoto Cooling heat wheel. The wheel, in the center of the diagram, spins between two chambers, exchanging heat as it is chilled and warmed by the airflows.
Heat wheels have been used in industrial cooling for many years, but were new to the data center when the Netherland-based KyotoCooling BV introduced its technology. KyotoCooling says its technology, which it has licensed to Air Enterprises in the U.S., is now installed in more than 100 data centers worldwide, including facilities for Hewlett Packard Enterprise, United Airlines, Bell Canada and Bend Broadband.
Colo Customer Wins
Adoption by colocation providers is valuable because these companies built multiple data centers around the world, and thus offer the benefits of scale and repeat business.
The QTS Chicago project is a good example. QTS Realty Trust has installed seven of the KyotoCooling units, which can each provide cooling for about 300kW of IT capacity. As the facility adds tenants and capacity, it will eventually feature at least 27 of the Kyoto units.
“We’re probably the largest implementation yet,” said Butch Goldi, Executive VP of Sales for QTS.
Goldi said the Chicago climate will allow the KyotoCooling systems to provide free cooling for up to 10 months out of the year, helping QTS achieve an expected Power Usage Effectiveness (PUE) of 1.19.
The Kyoto Cooling heat wheel is 15 feet in diameter, and turns at a rate of between one and six revolutions per minute. QTS delivers supply air at 72 degrees, with return air at 92 degrees.
A KyotoCooling unit at the QTS Chicago data center, where the systems are housed on a second-floor, above the data halls. (Photo: Rich Miller)
As QTS prepared to retrofit its Chicago facility (which was previously a printing plant for the Chicago Sun-Times newspaper), it got a close look at the KyotoCooling wheel in action at another Chicago-area facility.
“The construction team looked at the United (Airlines) data center,” said Goldi. “From a green perspective, it’s extremely efficient. It scales with your ability to grow the data center. It makes excellent economic sense, as it allows you to add capacity gradually.”
Flexibility Aids Design Wins
Several of the companies integrating Kyoto Cooling technology into their redesigns cited the fact that it’s not a new approach, which has provided a comfort level.
“It’s been used forever and it’s a proven product,” said Douglas Adams, the President of RagingWire Data Centers.
RagingWire adopted KyotoCooling for a new data center design. By using the Kyoto units in a roof-mounted configuration. RagingWire can offer dedicated cooling for each of its customer data vaults.
“Our design can operate with water or without water,” said Adams. “That’s important, because I don’t think there’s a guarantee of water being available in some U.S. markets.”
Positive PUE Impact
For Compass Datacenters, the shift to KyotoCooling allowed them to move the cooling units to the rear of the building. This allowed Compass to gain the flexibility to expand power and cooling capacity, which was previously limited by roof space. It also improves the energy efficiency of the building, a key consideration for cloud-scale players.
Compass CEO Chris Crosby expects the use of heat wheels will reduce the PUE of Compass facilities from 1.25 to 1.1
“It’s significant to drop nearly 0.2 on a PUE,” said Crosby. “That goes through to the bottom line. It’s not reliant on a perfect outside air environment, or impacted by humidity. Most of the solutions out there are very dependent on geography.”
KyotoCooling’s U.S. licensee Air Enterprises has also made some headlines this year for a lawsuit it filed against rival cooling vendor Nortek Air Solutions..
The two companies recently competed to win a contract to provide cooling products for a new data center design for Equinix, the world’s largest operator of colocation data centers. Nortek won the contract, only to have Air Enterprises file a lawsuit, asserting that Nortek’s indirect cooling unit, known as Cool3, contained a heat wheel that infringed upon its patents.
