Technical
NANOTECHNOLOGY FOR
BETTER REFRIGERATION HEAT TRANSFER
By Dr Bradley Bock , senior lecturer , Department of Engineering , Built Environment and Information Technology at the University of Pretoria
Nanotechnology may provide the breakthrough to push the HVAC & R industry towards the next level of performance and efficiency , and a team at the University of Pretoria ’ s Department of Mechanical and Aeronautical Engineering , in collaboration with colleagues from the Massachusetts Institute of Technology ( MIT ) and Imperial College London , are making progress on understanding this complex field and the possible applications to the HVAC & R industry .
The HVAC & R industry is under ever increasing pressure due to global warming , as the industry is estimated to be the cause of approximately 10 % of our global warming emissions 1 , either directly through the leaking of the refrigerants used in refrigeration equipment , or indirectly through the emissions at the power plants used to supply the electricity that operates these machines . Greater efficiencies are therefore essential to allow for lower electricity consumption as well as reduced equipment size so that less refrigerant is needed .
This is particularly true for Africa , which is expected to be the largest growth market for the worldwide HVAC & R industry 2 , 3 in the near future , driven by urbanisation and industrialisation 4 , 5 . This growth unlocks great potential for the African continent , particularly in the field of agriculture , where cold storage infrastructure will allow for the modernisation of Africa ’ s still often rural farming sector , reducing wastage and spoilage and expanding export opportunities . However , this growth will bring with it an even greater burden on global warming emissions , meaning Africa will have to be part of the charge to reduce the global warming impact of HVAC & R .
Nanotechnology may be part of the solution . Nanotechnology is any technology that operates on the nano scale , between 1 to 100 nm ( that ’ s between 0.000001 to 0.0001 mm ).
A wide range of technologies have been investigated , with advances in fields as diverse as solar panels , wastewater cleaning and cancer treatment 6 .
The team at the University of Pretoria are investigating nanostructures , nanometre-sized structures applied to surfaces to change their properties . These structures have properties that make them attractive for heat transfer , allowing for the possibility of more efficient and smaller evaporators and condensers .
The team at the University of Pretoria , consisting of Dr Bradley Bock and Prof Josua Meyer ( now at the University of Stellenbosch ), collaborated with researchers at MIT and Imperial College London to apply nanostructures developed originally for the nuclear industry to the outside of copper tubes used in refrigeration evaporators .
" A wide range of technologies have been investigated , with advances in fields as diverse as solar panels , wastewater cleaning and cancer treatment ."
1 https :// www . birmingham . ac . uk / Documents / college-eps / energy / Publications / Clean-Cold-and-the-Global-Goals . pdf 2 https :// www . designingbuildings . co . uk / wiki / Africa _ tops _ world _ AC _ growth _ forecasts 3 https :// www . goldsteinresearch . com / report / africa-air-conditioner-market-trends-analysis 4 https :// www . cbn . co . za / industry-news / food-dairy-processing-manufacturing / cold-storage-infrastructure-and-refrigeration-tech-are-key-for-growth-in-sa-foodproduction / 5 https :// www . newyorker . com / magazine / 2022 / 08 / 22 / africas-cold-rush-and-the-promise-of-refrigeration 6 https :// www . nano . gov / about-nanotechnology / applications-nanotechnology
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RACA Journal I March 2023 www . refrigerationandaircon . co . za