By Gillian Schutte
South African nuclear physicist Mojalefa Murphy has unveiled a ground-breaking invention that could transform how communities across the globe combat extreme heat. Known as Phokeng air cooling technology, this innovation harnesses enthalpy from the air—the combined sensible heat of the sun and the latent heat of evaporation—to cool indoor spaces with minimal energy and without harmful refrigerants. Remarkably, it can function on a mere 60 watts of electricity, roughly a tenth of what most conventional air conditioners consume, and can even run entirely off-grid using a single solar panel.
Beyond its scientific ingenuity and wide application potential, Phokeng embodies a deeply personal mission. Murphy is determined that the technology should first serve underprivileged communities—especially hospitals, schools, and remote data centres—so that those with limited resources can also benefit from advanced, sustainable cooling. By indirectly cooling air to the dew point through alternating wet and dry channels, Phokeng can bring down temperatures from as high as 90°C to around 19°C, and in regions with less than 60 percent relative humidity, it can even cool the air to approximately 16°C. Such capabilities offer vital relief in areas where standard air conditioning is too expensive or absent.
Murphy’s commitment to uplifting marginalised communities is deeply rooted in his upbringing. Born in Evaton in the then-Transvaal, he grew up in a family proud of its Basotho heritage. His mother, Eleanor Maseemane Mofokeng, juggled dressmaking and running a shebeen to support her eight siblings. His father, Abram Molele Makume, known as Bra Abe, came from George Koch, tracing roots to Lesotho and the Orange Free State. Their example taught Murphy resilience, compassion, and a strong sense of social responsibility.
As a teenager in 1977, he was stirred to political action by the murder of anti-apartheid leader Steve Biko. While a student at Tseki Senior Secondary School in Witzieshoek, he organised a memorial service for Biko, a move deemed subversive under apartheid law and leading to his expulsion. Forced to flee to Lesotho, he completed his secondary education at Bereng High School in Mafeteng before enrolling at the National University of Lesotho. Political tensions soon pushed him further abroad, and he relocated to Canada to pursue a Bachelor of Science (Honours) in Applied Physics at the University of Manitoba.
Driven by a desire to aid in South Africa’s liberation, Murphy returned to southern Africa in 1986. He lectured at the University of Bophuthatswana in Mafikeng while training in medical physics at Hillbrow Hospital in Johannesburg. There, he discovered how nuclear and radiation sciences could be channelled into treating cancer—a revelation that married his passion for physics with his humanitarian ideals. Yet the perils of apartheid still lingered. Arrested at a roadblock in Rooigrond, he was compelled to flee once again, this time to the United Kingdom, where he specialised further in radiation and nuclear physics at the University of Surrey.
With the end of apartheid on the horizon in the early 1990s, Murphy returned to a rapidly changing South Africa. He joined the Atomic Energy Corporation, aiming to redirect its focus toward the social and economic needs of the new democracy. Finding himself at odds with entrenched interests, he was dismissed under allegations he felt were contrived to derail his reformist goals. Soon after, Professor John Sharpey-Schafer enlisted him at the National Accelerator Centre, later known as iThemba LABS, where he advanced research in medical imaging, radiotherapy, and training for underrepresented groups. Another dispute over governance led to his second dismissal, effectively closing off scientific opportunities for him in South Africa.
Disillusioned but undeterred, Murphy relocated permanently to Canada in 2003 with his wife, Judit, and their children, Toka and Julia-Nala. Legal battles to clear his name and a tarnished record made it difficult to revive his scientific career. Still, he made yearly visits to Evaton to see his mother, providing crucial support and remaining closely tied to home. In 2022, she fell seriously ill. On her deathbed, she issued a striking prophecy, urging him to set aside past grievances and use his expertise for Africa’s benefit.
Soon after his mother’s passing, Murphy himself was diagnosed with a rare small-bowel cancer complicated by H. pylori. Frustrated by long wait times for scans in Canada, he returned to South Africa for swifter imaging—an irony not lost on the physicist, who had once struggled to embed his expertise within the very country now aiding his diagnosis. Throughout his treatment from 2022 to 2024, he worked to finalise Phokeng air cooling technology, devoting himself to an invention that he believes will answer his mother’s parting wish.
Phokeng’s core design uses composite walls with hydrophilic and hydrophobic properties in adjacent channels. Evaporation in the wet channels reduces heat, indirectly cooling the dry channels and pushing temperatures below standard evaporative limits. With only 60 watts of energy consumption, the system avoids using refrigerants that contribute to global warming and can operate solely on solar power. Murphy foresees countless applications for Phokeng—ranging from motor cars and large shopping centres to power stations—but insists it be deployed first where people are most vulnerable.
By planning the launch of Phokeng primarily in South Africa, Murphy aims to fulfil the prophecy delivered by his mother: to harness his knowledge in service of the continent. His journey from a passionate student activist exiled for honouring Steve Biko, to a nuclear physicist twice dismissed by institutions, to a resilient inventor determined to help communities in need, forms the backdrop to Phokeng. As a testament to his enduring commitment and the power of scientific ingenuity, Phokeng stands ready to bring hope and relief where it is most urgently required.
First Published on Sunday Tribune 2 Feb 2025