A hybrid cooling system for telecommunicatioin base stations

Abstract

Huge amount of energy is consumed by a typical telecommunication base station in order to keep the indoor climate temperature low enough to avoid any damage to IT/electronic equipment. By increasing the number telecommunication base stations applying more energy efficient cooling strategies are urgently needed. Free cooling either in direct approach (e.g. extracting fresh air), or indirect approach (e.g. thermosiphon or air to air heat exchanger) is a well-proven strategy to reduce the total power consumption for cooling telecommunication base stations. This article proposes a hybrid cooling system, which is an integrated vapour compression unit with a thermosiphon unit in a single frame. In such a hybrid system the indoor air circulates through a closed loop with minimal interaction with the outdoor air. This article suggests a model to control and estimate the potential of energy savings by a hybrid cooling system. Based on the results for an indoor temperature set point of 25 °C the cooling load provides by the hybrid system can be divided among three different operating modes: 0–59% (thermosiphon), 12–41% (dual mode), and 12–88% (air conditioning) depending on the location of the base stations.