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Data Centers Work To Reduce Water Usage
miller60 writes "As data centers get larger, they are getting thirstier as well. A large server farm can use up to 360,000 gallons of water a day in its cooling systems, a trend that has data center operators looking at ways to reduce their water use and impact on local water utilities. Google says two of its data centers now are "water self-sufficient." The company has built a water treatment plant at its new facility in Belgium, allowing the data center to rely on water from a nearby industrial canal. Microsoft chose San Antonio for a huge data center so it could use the local utility's recycled water ('gray water') service for the 8 million gallons it will use each month."
RTFA. The water loss is because many data centers use evaporative cooling towers.
That's the point - the water does get consumed. The simplest (cheapest) way to cool the water after running it through the data center is to use evaporation towers. As the name implies, you lose a substantial portion of the water to evaporation. Evaporation towers are very efficient in terms of power and material costs, but they go through a lot of water. Costs a lot more to construct a closed-loop system - you need some sort of giant radiator to cool the water. Evap tower you just build a hollow box, put some sprayers at the top, a collector at the bottom, and off you go.
I'm guessing you must not be from the US because evaporation based cooling systems are THE standard for state of the art industrial and commercial cooling in the US. If you have over 250 tons of load, you have an open cooling tower - dead standard ASHRAE design. The evaporation of water via a cooling tower is THE way you reject heat. If you want to do it dry (as is common in Europe due to much higher fear of Legionella and local code officials freaking out about it), it is FAR less efficient in almost every case, even in monsoon climates like Banglore a wet cooling tower is more efficient.
An annoying fact of physics is that when it gets really cold, evaporative cooling becomes less effective. The air just can't hold much water, and it's the phase change from liquid to vapor that gets rid of your heat. So, it's not freezing that make low temperatures worrisome but actually loss of capacity.