- Warm water system for direct cooling of computer nodes (four DLC cabinets)
- Cold water system for general component cooling and four data center air-conditioners.
The warm water system prepares the cooling water in order to cool 4 computer node cabinets in 35/40°C mode. The system maintains a constant inlet water temperature of 35°C with a three-way control valve and a hydraulic switch that compensates larger changes in incoming water temperature.
The cold water system prepares water for 4 enclosures in the data center in 10/15°C mode. Two air-conditioners are placed in line with supercomputer cabinets. At the back, a warm zone is created in which the air temperature is higher than 35 ° C. Hot air enters the air-conditioned enclosure which cools it to a set temperature of 24 ° C. The cooling system has a double floor used for the UPS cooling and this system is also used to maintain the desired humidity. Cabinets are 100% redundant.
The hot water system has two 127 kW water coolers, while the cold water system has two 87 kW water coolers. The total data center cooling capacity is 210 kW and an additional 210 kW in redundancy. Both systems have freecooling capability. The hot water system depends on the outside temperature (27°C is the threshold) since the cooling water is kept at 35°C. Computer nodes are typically cooled in the freecooling mode (without active cooling for temperatures up to 27°C) throughout the year, depending on the weather conditions. The changeover from forced cooling to freecooling cooling is done automatically when the conditions for one or the other for each system are met separately.
The cooling system utilizes 10 pumps, 16 motor locks and one 3-way valve. The system is fully automated and controlled. The system has 45 relays, over 110 different sensors on digital and analog inputs and outputs while all active equipment is connected via Modbus protocol.
The data center PUE factor is 1.24. The PUE factor was measured when testing the supercomputer at 100% load with the hot water system running in freecooling mode and the cold water system in forced cooling.