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
