Review of Waste Heat Utilisation from Data Centres

Rapidly increasing global internet traffic, mobile internet users and the number of Internet of Things (IoT) connections are driving exponential growth in demand for data centre and network services, which in turn is driving their electricity demand. Data centres now account for 3% of global electricity consumption and contribute to 4% of the global greenhouse gas emissions. This study discusses the potential of reusing the waste heat from data centres. An overview of imbedding heat recovery systems into data centres is presented. The implications of economic cost and energy efficient heat recovery systems in data centre buildings are also discussed. The main problems with implementing heat recovery systems in existing data centre designs are (i) high capital costs of investment and (ii) low temperatures of the waste heat. This study suggests alternatives that could allow data centre operators to utilise waste heat with more efficiencies. It also discusses how liquid-cooled data centres can be more efficient in utilising their waste heat than the air-cooled ones. One possible solution suggested here is that data centre operators can decrease their environmental impact by exporting waste heat to the external heat networks. The barriers in connecting datacentres to heat networks are discussed and suggestions to overcome those barriers have been provided

Prediction of Thermal Performance of Glass Roof Atriums using CFD Modelling

Glass covered or glazed atriums are becoming increasingly popular in public spaces for their aesthetics, quick installation and building energy reduction by taking advantage of natural daylight and heating by greenhouse effect. The estimation of the building load of atrium buildings is complicated due to the various thermal phenomena involved. The study aims to estimate the cooling loads or heat gain of glazed atriums, using computational fluid dynamics (CFD) modelling using an actual semi-open pedestrian walkway between two building blocks. Steady Reynolds Averaged Navier Stokes modelling approach with the RNG K-epsilon turbulence model, and the Discrete Ordinates (DO) Radiation models were used in the simulation. The temperature and air flow patterns predicted by the CFD simulations are discussed in this paper under various weather conditions. Results predict temperature gains inside the atrium, identify hot and cold spots and predict thermal comfort