Market Insights

Will Running Data Centers Hot Lower Costs?

December 01, 2023 by David Weldon

Data center managers had mixed reactions when asked by EE Power about a study that recommends running centers at higher temperatures. Read what they had to say about equipment, risks, costs, and savings.

A recent study at Hong Kong Polytechnic University found that if data center managers want to save money on operational costs, they should “turn up the heat,” and run the data center at higher temperatures.


Data center.

Data center. Image used courtesy of the U.S. Army

But that advice was met with mixed reviews from data center managers. One manager told EEPower, “Definitely not,” another said, “Yes, but,” while a third stressed a “definite maybe.” The varying responses depend on how old the center’s equipment is. And the advice may apply more to data centers that have not yet been built.


About the Polytechnic Study

The Hong Kong Polytechnic study said that raising a data center temperature to 41°C (around 106°F) can save up to 56% in cooling costs by relying on free-cooling. That process uses ambient air to cool the water in air conditioning systems.

The study’s author, Shengwei Wang, stated that redesigning servers to function at higher temperatures could reduce energy costs for cooling systems.

The study proposed new temperature guidelines to aid organizations in developing and managing more efficient data centers in the future.


When Is Hotter Too Hot?

Matt Thoene, president and CEO at Onevisory, a strategic advisor and data center industry analyst, agreed with the study recommendations.

“I actually do agree—as long as the servers, switches, routers, etc., in the facility, are all less than three to five years old and capable of running at these temperatures,” Thoene told EEPower. “However, if you are running a multi-tenant colocation facility, there definitely needs to be an upfront conversation and disclosures about the heat levels.”

Thoene said his organization increased temperatures—between 3 to 5 degrees—on two different occasions in its 80,000-plus square foot data centers and saw “more than trivial” savings in power costs. 


Data center manager.

Data center manager. Image used courtesy of NIEHS


George LaRose, director of data center operations and hosted services at Northwell Health, told EEPower equipment age is critical.

“With respect to a ‘super hot’ data center, I would think this facility has to be a green field or retrofit of a modern data center,” LaRose explained to us. “Most data centers are not designed from the ground up. One of the largest challenges is to create the air plenum space/volume to allow for the intake of cooler air into the infrastructure—even if that ‘cooler air’ is now 40% warmer. Of course, this approach assumes forced air or a ‘fan wall’, and static pressure is being used to move air. A dual approach of liquid cooling in concert with cold aisle containment may also offer a viable design.”


Pros and Cons of Running the Data Center “Hot”

The benefits of running the data center at higher temperatures would be a precipitous decrease in operating expenses, resulting in increased earnings. 

But beware, cautioned Bill Wolff, data center manager at a major global furniture manufacturer and retailer. The more you raise the temperature, the more the fans in the servers increase in speed, utilizing much more energy.


“‘Mean time between failure’ goes down when the temperature goes up. Heat wears on electronics.” - Bill Wolff, data center manager


“I know a data center that raised the temperature up to about 86-plus degrees Fahrenheit,” Wolff told EEPower. “A Cisco chassis supervisor board—the brains or processor—literally melted down. Cisco was unable to do any forensics on the board since it was cooked. Also, disks and other server components run hotter inside than the input temperature, such as spinning disks. Open a running server and put a heat gun laser measure on it, and it will read it at 20-plus degrees hotter. Also, ‘mean time between failure’ goes down when the temperature goes up. Heat wears on electronics.”


Advice to Data Center Operators

Conversations about energy efficiency and savings in data centers with the most momentum are around liquid cooling and renewable energy alternatives. That includes small modular reactors, Thoene said.

“These are longer-term solutions, of course,” Thoene explained. “In the short to medium term, data center operators should focus on proper airflow management, battery or hydrogen power backup versus costly generators, and higher efficiency cooling systems using air-cooled vs evaporative as an example. Additionally, integrating AI with DCIM (data center infrastructure management) to automate and optimize the management of power and cooling as well as capacity planning.”

Thoene advises operators to take time to educate customers on operational options and what the cost impact of each would be. Operators should explain how high temperatures are acceptable and will not fry their equipment.

“You will most definitely receive pushback if you intend to implement a 30-plus degree increase in temperature, so be ready for those conversations,” Thoene said. “For the standard data center operator, just ensure that your gear is rated to handle these levels. If they are, you have very little to worry about.”