It is also remarkable that, while the conventional heating, ventilation and air conditioning systems (HVAC) for similar size rooms deal with heat fluxes in the order of 40-90 formula_1, cooling systems in data centers work with extremely higher heat loads: modern data center infrastructures can need to refresh apparatus that produces 6-10 formula_3 as power density. In the next few years, it is estimated that the power density consumption will still raise up to 15 formula_3.