0.0 kW
Cold supply air and chilled waterAir heated by the serversRaised floor, racks, return ductFour racks of twenty servers draw 9.6 kW idle and 36 kW flat out (120–450 W each). Every watt becomes heat, so the server fans pull cold-aisle air at 22 °C through the racks, up to 5271 CFM at full load, and push it out about 12 °C hotter. The hot aisle is closed in, so the hot air can only go up into the return duct and back to the air handler. There a chilled-water coil takes the heat out and the blowers send the air back under the floor. The building also pays for UPS losses, chillers, fans and lights; PUE (total power ÷ IT power) stays near 1.35. Dimensions in centimetres.