Cooperative control architecture of fan-less servers and fresh-air cooling in container servers for low power operation

In order to minimize the container server power consumption, a new cooling system that incorporates fan-less servers and freshair cooling is proposed. In a conventional container data center, the required air flow for sever cooling is supplied by both server built-in fans and container facility fans. Therefore, this work has been carried out on fan-less servers to reduce power consumption. Although fanless servers are expected to reduce power consumption, facility fans have to provide excessive air to secure a safe operation of servers. In order to achieve optimized air-flow from facility fans to cool fan-less servers, a power saving control system incorporating the IT system and cooling facilities is proposed. Here, facility fans are controlled based on server information such as CPU temperature, rack position and so on. Through this study, we suggest that the minimum point in total power consumption of the container server with no performance penalty existed by the trade-off relationship between the power consumption changes of servers and of facility fans with CPU temperature. This enables us to operate the server system with minimized power consumption depending on the air temperature. To verify the energy-saving effect of this technology, a prototype container server with the proposed system was constructed. As a result, 22.8% energy saving was achieved with this new system, compared with the conventional container servers with built-in fans.