Wireless sensor network applications

WSN for monitoring temperature distribution in data centers

Continuously monitoring the spatial temperature distribution in an air-cooled data center (DC) is important for reliably operating the computing equipment and minimizing the required cooling energy. For this purpose, we designed and developed a wireless sensor network (DCWSN) solution that captures the temperature at selected key locations in the DC room with low-cost battery-powered sensors, forwards the captured information from the sensors via relay nodes to a monitoring client using IMPERIA/MQTT-S networking functions, and iteratively generates interpolated temperature maps on the client computer. The DCWSN solution is offered to IBM internal and external customers.

The usefulness of the developed DCWSN solution has been demonstrated in various measurement campaigns that we performed at the IBM Research - Zurich Laboratory data center and at the IBM DC center in Geneva.

At the IBM Research - Zurich Laboratory DC, we traced the temporally changing temperature distribution in the plenum after spreading 50 wireless temperature sensors in the under-floor plenum of the DC. A short-term hot-spot below a server rack was identified. By mounting 48 temperature sensors close to a single rack, we measured typical temperature distributions at the server inlets and outlets of a typical rack to identify critical thermal zones. Finally, we mounted a temperature sensor at the front side of some racks in the DC, captured the temperatures with the DCWSN and generated from the measured information interpolated temperature maps. The maps match well with those that we obtained by performing a survey with IBM's Mobile Measurement Technology (MMT).

At the IBM DC in Geneva, we installed a DCWSN with 108 sensor nodes to trace the temporally changing temperatures in the DC room during a cooling system upgrade, which has been performed by the operator to reduce the energy consumption of the DC cooling system from 3,600 to 1,500 MWh per year. During the 5-week upgrade, the DCWSN performed reliably. Several potentially harmful hot spots were detected and eliminated by improving the air-flow distribution in the room. Owing to the successful deployment of the ZRL real-time temperature monitoring solution, the DC operator is considering the permanent installation ofthe DCWSN to minimize the increased risk of overheating servers in the new energy-optimized operating environment.

Related publications

  1. B. Weiss, H.L. Truong, W. Schott, T. Scherer, C. Lombriser, and P. Chevillat, "Wireless Sensor Network for Continuously Monitoring Temperatures in Data Centers," IBM Research Report, RZ 3807, June 2011.