Executive Summary
- A common myth is that facilities need to be very cold to keep hardware from malfunctioning, when actually that’s just the meat locker myth that has our thinking stuck in the 80s.
- If data centres were a little bit warmer – and we’re talking a few degrees here, not Spanish weather – operators can employ the use of economisation and reduced use of mechanical refrigeration to save on operational expenses and increase efficiency.
- Operators must apply this to their facilities on a case-by-case basis to see where they can reduce cooling costs and increase PUE.
A common misunderstanding around data centre temperatures is that facilities need to be very cold to keep hardware safe and prevent it from malfunctioning. However, this notion is pretty outdated, and this way of thinking keeps you stuck in the 1980s, when hardware would malfunction if the room was hotter than optimal.
For decades, operators have been intimidated by heat and thus maintained a “meat locker” environment of 18 degrees to 21 degrees. However, with today’s advancements, we no longer need to adhere to this temperature, and it’s simply a psychological holdover from the 1980s.
We’re conditioned to believe that cold means it’s “safe” and heat is the devil incarnate for hardware; this article explores that the biggest barrier to greener data centres is the fear of the person holding the thermostat.
What happens when we turn up the dial?
If data centres were a little bit warmer – and we’re talking a few degrees here, not Spanish weather – operators can employ the use of economisation: the process of using outside air rather than mechanical chillers for most of the year, which could save on power used to keep data centres cool.
While ASHRAE A4 has updated its guidelines to include an “allowable” range of up to 45°C, that doesn’t mean it’s completely recommended (the range for that is 18-27°C).
In Google’s 2008 “Data Centre efficiency” white paper, they state that the need to operate data centres at 70°F was a myth and they famously raised their temperature to 80°F (27°C). Their findings showed that the energy savings from reduced chiller use outweighed any minor increase in server fan energy drastically.
Temperature increases can result in reduced cooling costs
In the Uptime Institute’s 2025 study, it shows PUE is plateauing, with it stalled at 1.54, because operators aren’t looking for the easy wins in the face of efficiency, like turning that thermostat ever so slightly. Per 1°C temperature change could result in energy savings of around 4-5%.
Historically, cooling failures are roughly 13-19% of significant outages and the 2025 study indicates that it’s ranked as the second most common cause of facility-level failure, at 14%.
Data centres are at risk of overcooling their facilities when they don’t need to, especially with the ASHRAE compliance regulations updated for 2026.
They have a recommended and allowable environmental limits and that’s the core distinction they wanted to make for 2026 with their ASHRAE TC 9.9 implementation. The goal is to achieve long-term reliability and energy efficiency and it can be hard to navigate the fine line of balance between increasing efficiency and preserving the lifespan of hardware while reducing downtime.
The wider rangeles enable facilities to operate year-round without the need for mechanical refrigeration and save on operating expenses and increase efficiency. However, operators must apply this on a case-by-case basis and anticipate the results of their facilities, because extended operation in allowable ranges (and not the recommended ones) may impact the reliability of equipment and increase energy consumption through higher fan speeds.
The Price for Peace of Mind
Our obsession with over-cooling is costing us dearly; we’ve spent 40 years in the meatlocker, so stepping out into temperatures from 22 to 27 degrees will feel like a gamble.
But with the Uptime Institute’s 2025 Global Survey revealing a global PUE plateau of 1.54, we’re burning megawatts of energy to protect hardware that can handle higher temperatures.
As regulations tighten and energy efficiency needs to increase globally, are we still willing to pay the price of overcooling our data centres just for our peace of mind?
