DATA CENTRES | COOLING THE POTENTIAL FOR DEW POINT COOLING A dew point indirect evaporative cooler developed by researchers in Hull aims to reduce electricity consumption in data centres and other buildings significantly. PhD student Cheng Zeng looks at the performance of a system at the Maritime Data Centre R esearchers at the University of Hull have developed a super-performance dew point cooler that can save 90% in electricity consumption compared with traditional mechanical vapour compression and evaporative cooling systems. With a coefficient of performance (COP) of 52.5, the cooler can also save 50% compared with an evaporative cooling system. From 2019 to 2021, the Centre for Sustainable Energy Technologies at the university worked with several partners to deliver a demonstration project that uses the dew point cooling technology in a live data centre in Hull. This case study looks at a real-life application of the technology, and shows how it can achieve a significant impact in reducing energy consumption and carbon emissions for data centre cooling. The aim was to demonstrate a 100kW superperformance dew point cooling system in a live data centre that could remove a significant amount of heat dissipated from the IT equipment, while maintaining an adequate space temperature in the data centre. The dew point cooling technology, as a form of indirect evaporative cooling (IEC), cools the air using the principle of water evaporation. This results in significant energy savings and further temperature reductions compared with more conventional technologies. The case study is directly relevant to data centre space cooling, although the technology can also be applied to other types of buildings, such as greenhouses and railway stations. The innovation The core technology of the demonstration project is an innovative super-performance dew point cooling technology. The dew point cooling process is based on an IEC heat and mass exchanger, as shown in Figure 1. During operation, the intake air flows into the dry channels of the exchanger. The air moves forward along the dry channel and loses heat to the adjacent wet channels because of the temperature difference established between the channels and water evaporation on the wet-channel wall. At the end of the dry channel, the air is divided into two parts. One fraction of the airflow the product air is delivered into the conditioned space for cooling, and the other fraction the working air is diverted into the adjacent wet channels for water evaporation. Within the wet channels, the working air moves backwards, absorbing the heat transferred from the dry channels and receiving the moisture evaporated, thereby completing a heat and moisture Product air (cool air) Servers Heat exchanging unit Dew point cooler unit Exhaust air Hot air returns to cooler Dew point cooler in data centre working principle Water tank www.cibsejournal.com April 2022 55 CIBSE Apr 22 pp55-56, 58 Dew point cooler.indd 55 25/03/2022 18:01