Evaporative Cooling Helps Data Centre Lower Its PUE

EcoCooling’s evaporative cooling system has helped a Manchester-based data centre reduce its PUE rating to just 1.18, saving more than 1,000 tonnes of carbon each year.

The co-location facility known as M247 was formerly running at a PUE (Power Utilisation Efficiency) rating of 1.6, using a refrigeration-based air conditioning system to cool its IT equipment.

In a bid to cut down on energy consumption, the company consulted British-based firm EcoCooling Ltd, which introduced a more natural way of producing cool air – evaporative cooling.

Evaporatively cooled retrofit solution

Evaporative cooling uses the drop in temperature that occurs when water that has been exposed to moving air begins to vaporise and change to gas. An evaporative cooler is in essence a large fan that draws warm air through water-moistened pads. As the water in the pads evaporates, the air is chilled and pushed out to the room.

According to EcoCooling, its evaporative cooling system uses 90 percent less energy than traditional refrigeration units, while keeping the IT equipment at a constant temperature.

The new installation and control software has enabled M247 to achieve PUE as low as 1.18, while keeping internal temperature below 20^oC throughout the summer. This is substantially lower than the refrigeration-based system’s performance, which cannot go below 25°C in bouts of high temperatures.

“We have achieved PUE below 1.2, exactly as planned,” said David Buckle, director of M247. “The benefits began immediately”.

With 14 evaporative coolers retrofitted, the facility can save more than £130,000 worth of electricity and over 1,000 tonnes of carbon every year.

Hot Aisle Containment

Encouraged by the improvemed performance of M247, the company is now considering a new facility equipped entirely with EcoCooling evaporative cooling units, as well as a hot aisle containment system that could push its PUE below 1.1.

Most data centres incorporate a hot aisle/cold aisle configuration, where equipment racks are arranged in alternating rows of hot and cold aisles.

This practice allows air from the cold aisle to wash over the equipment before getting expelled into the hot aisle. At this point, an exhaust vent pulls the hot air out of the data centre.