During the winter, we create more cooling capacity with the cooling towers than is needed for the data center with these cold temperatures. This additional cooling capacity is pumped down into aquifers at a depth of approximately 175 meters beneath the ground.
This stored cooling capacity is saved for use during the summer when the cooling towers are unable to create enough cooling capacity due to the warmer outside temperatures.
What about ice on the cooling towers ?
In total, here at Schuberg Philis, we have four fans on our cooling towers. The issue with the winter months is that we over cool, and ice begins to form. When too much ice starts to build up, we use a novel way to remove it. Usually, the fans run at 50 Hz, pulling cool air in from the bottom and pushing it up into the air. To remove the ice, we restart one of these fans, this time at 7.5 Hz but this time spinning in the opposite direction. With this, the cooling tower continues to get warm water from the data center, but instead of cooling the water by pushing it up through the fans, this warm water now drips through the cooling tower, melting the ice and de-icing that part of the cooling tower.
After 15 minutes of operation, we power-off the fan again and restart it in normal operation mode before moving onto the next fan. After all four fans have been restarted, an hour later all of the ice is gone from the cooling towers.
Making use of the heat in the data center to remove the ice on the cooling towers is a very energy efficient way, which allows us to continue to operate a peak efficiency without damaging our cooling towers.
Using heat from a data center