Cool IT: a new use for CO2

Carbon dioxide offers a new optimum cooling medium for IT facilities. Electrically benign, and therefore non-hazardous to servers and cabling, it is seven times more efficient at cooling than water: CO2 permits reduced volume flows and smaller diameter distribution pipes, heat is absorbed during a phase change process with no rise in temperature. Furthermore, energy savings can be made on pumping power given that it has lower viscosity and volume flows than water. Developed by Trox in collaboration with Star Refrigeration, the CO2 OLrac system design circulates CO2 at a temperature of 14°C, above dew point, thus avoiding condensation. The liquid CO2 absorbs the heat across the coil and evaporates to a vapour which is held in suspension. The unit is fitted with 5 fans and a digital temperature display to provide a visual indication of the off-coil temperature in each cabinet. It can satisfy equipment loads up to 30 kW per cabinet.