This 123-year-old air-con system has lessons for managing today's sweltering heat

As climate change roasts cities around the world, air conditioning can be the difference between life and death for vulnerable people – but it comes with heavy costs. The long history of air conditioning in public spaces shows what is at stake.

There is a giant six-blade fan in the brick wall before me. The fan, painted a glossy red and set neatly into a circular hole in the wall, must weigh multiple tonnes. But when I put my hand on one of its blades, it turns easily – without so much as a squeak, as though it were installed yesterday. The slightest breeze wafts down from the contraption as it slowly decelerates, returning to a halt.

"Amazing isn't it," marvels Alan Luney, senior estates officer at Belfast's Royal Victoria Hospital in Northern Ireland. "After all these years, that you can spin that. I mean, there's not a noise out of it."

I'm standing inside a 123-year-old air conditioning system made of brick and iron. Installed in 1903 to cool now-demolished original wards, this system made the Royal Victoria Hospital one of the first mechanically air-conditioned public buildings in the world.  

The fan once drew air across a jungle-like arrangement of coconut fibre ropes that were regularly moistened with cool water in the summer. That air then flowed along a 150m-long (490ft) corridor with an upwards-sloping floor. Openings in the corridor's walls allowed temperature- and humidity-controlled air to reach hospital wards above, through hidden ducts.

The aim? To improve patient recovery times and, ultimately, save lives.

With global temperatures rising and heatwaves becoming ever more extreme, the role that air conditioning plays in public health has become increasingly important. The need is clear. High temperatures, besides sometimes being deadly, may also make people more aggressive, or adversely affect their decision-making. Heatwaves can even reduce the efficacy of certain medicines. Public access to cool spaces is being promoted by many cities worldwide, with some even installing purpose-built, air-conditioned climate shelters.

But to really understand the significance of air conditioning as a health-preserving intervention, you should turn to its historical origins.

Although the Royal Victoria Hospital's giant fan and coconut fibre cooling system has since been superseded by more modern and more hygienic technology, it remains a testament to the life-saving power of air conditioning. Access to air-conditioned buildings drastically reduces the risk of heat-related mortality and one study found that each year, air conditioning averts around 195,000 deaths globally among people older than 65.

"Cooling is the number one most important approach to reduce the health risks of heat – and often what's required is air conditioning, or active cooling," says David Eisenman, a physician and health researcher at the University of California Los Angeles' Fielding School of Public Health.

In hospitals, air conditioning can play a vital role, reducing the risk of patients dying by up to 40% in extreme heatwaves. Hospital cooling equipment failures are treated as "critical incidents" during hot weather.

The origins of air conditioning

Florence Nightingale, nursing pioneer and social reformer, promoted various hygienic interventions, including the freshening of air in 19th Century hospitals. Most doctors and nurses achieved this at the time simply by opening the windows.

The architects of the Royal Victoria Hospital's wards in 1903 sought to create a healthy environment in a city where infant mortality was high and pollution from factories and mills was diabolical. The water-soaked coconut ropes not only cooled incoming air, they captured soot and dust, too.

"It was about creating what we would call a hygienic environment," says Nigel Keery, head of estates operations at the Belfast Health and Social Care Trust. "That involved not having to open windows where coal dust and soot was coming in."

The resulting system – parts of which were made by the same company that manufactured ventilation fans for the Titanic........

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