Energy saving active cooling systems for outdoor cabinet

Currently the energy-saving strategy is one of the top priorities of Telecom Operators and Governments. In particular, the area of cooling has heavy impact on the total electrical energy consumption, and needs to be optimized to improve overall performances, reducing both CAPEX/OPEX and the environmental impact. In this paper, two innovative cooling solutions for outdoor cabinets are described: free cooling system and manhole cooling system. Free cooling system is a solution directly using external fresh air in order to increase the cooling efficiency of active outdoor cabinet. Three key technologies are developed and used in this system: experimental results indicate that excellent heat dissipation capacity and good corrosion resistance of outdoor cabinet are achieved simultaneously. Manhole cooling system is another innovative solution, in which manhole (part of the underground maintenance infrastructure of TLC operator) is innovatively used as a huge heat sink. The cooling performance of manhole cooling system is predicted through CFD simulations. It has been demonstrated that as much as 60% of the heat load can be dissipated into the ground, still maintaining the equipment well within its operating temperature range. The proposed cooling solutions are particularly interesting for the FTTCab architecture. FTTCab deployment, as foreseen in several NGN strategies, will strongly increase in the next years.