Another legacy cooling technology in data centers is what’s called a cooling tower. A cooling tower sits outside of the main building, and the water cascades down these towers like a waterfall. However, the tower is open to the atmosphere to let natural cooling in. The churn of the water dissipates the heat, but there is significant evaporation in the process.
“It evaporates a lot. I mean, we’re talking many, many Olympic swimming pools worth of water on a daily basis in some of these data centers,” said Green. “Some of the hyperscalers I work with are still using open cooling tower solutions, even today.”
There were other reasons for using evaporation. For starters, evaporation equipment takes up a lot less space the chilled water equipment. Secondly is the price. Chilled water-cooling costs about 10% to 15% more than equivalent evaporation technology.
But that is changing, Green notes, as more and more societal pressure, economic pressure around water consumption continues to move to the forefront, data centers are being forced to adapt.
“We’re in a market now where we can use air cooled chillers that don’t evaporate water like a water-cooled chiller does, and have a very, very similar level of overall system efficiency,” he said.
We are also seeing the advent of closed loop technology, where liquid is pumped into a system to absorb heat and then pumped out to be cooled and recirculated, much like a car radiator. Gamers have been on the forefront of liquid cooling and closed loop with all-in-one coolers for gaming PCs becoming standard issue now.
