A mechanical engineer at Qatar University used giant tanks of cold water to create a cooling system in one of the hottest places on the planet.
DOHA, Qatar — Saud Ghani knows cool.
In his air-conditioned Porsche, he pulled up to a shady spot at Qatar University. He entered one of the many laboratories in the engineering department where he studies thermal dynamics — mainly, how to keep people comfortable in a warming world.
Even his title is cool: professor and chair of air conditioning.
The university’s campus was empty because the semester had been suspended for the World Cup. The temperature outside was about 90 degrees Fahrenheit. The indoor labs were noticeably chilly.
This was the quiet epicenter of what became a global story of audacity. This is where Ghani and his associates oversaw the design of systems that dared to air-condition the eight outdoor World Cup stadiums in and around Doha, one of the world’s hottest big cities.
“People think, oh, you have too much money and you’re just pumping cold air,” Ghani said. “That is not it at all. But what can you do? If people want to criticize from the sideline, I think that’s an oversight. But if they want to learn, they are 100 percent welcome here.”
So Ghani set off on a private tour.
He wanted to show the scaled replicas of each stadium, most of them tweaked during the design stages — at Ghani’s behest and to the architects’ chagrin — to better keep out hot air. He wanted to show the garage-sized wind tunnel and smoke and laser lights used to examine how air would circulate through each design. He wanted to show the miniature model of bleachers, with little hollow humans made on a 3-D printer and steadily injected with warm water — at 98.6 degrees Fahrenheit — to simulate body temperatures, and where infrared cameras could tell which of the fake people were too warm or too cool.
“I want people to feel neutral,” Ghani said. “I don’t want them to feel cold. I don’t want them to feel warm. It’s about perception. It’s not just temperature. But how do they feel?”
This Goldilocksian pursuit raised plenty of questions. Not the least of them are two big ones:
Did this man, in these labs and at this World Cup, just alter the future of stadium design in a warming world?
Could open-air stadiums that keep athletes and spectators comfortable at room temperature, no matter the heat of the day, exist?
Ghani shrugged off the first one. He said yes to the second.
A City Humming With Cool
Ghani, 52, is from Sudan and got his doctorate in mechanical engineering at the University of Nottingham in England. Married with three children, he came to teach at Qatar University in 2009, just as the country was preparing its long-shot bid for the World Cup.
One day he got a call from Qatar’s highest levels: Can you design a system that keeps people cool, even in an outdoor stadium, even in Doha, even in the summer? The bid’s success, or failure, might rest on it.
Sure, Ghani said.
In 2010, Qatar won the right to host this year’s tournament, for reasons that have to do with corruption more than thermal dynamics.
In 2015, acknowledging that scorching temperatures, in and out of stadiums, could be both miserable and dangerous, FIFA moved the competition from its traditional summer dates to late fall. The change may have made Ghani’s mission easier, with daytime temperatures in the 80s and 90s instead of 110 or higher, but he insisted that it did not matter.
These eight stadiums of various sizes and designs were not just for the World Cup. One will be dismantled, but seven will be used, year-round: for big events, for club teams, for university athletics, maybe even as part of a bid for the Olympics. (Such promises for everyday uses can go unfulfilled, as the ghost venues of past Games attest.)
In Qatar, the heat for nine months of the year is almost unbearable, Ghani said. And it is not going to get better.
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“Is it smart from a sustainability standpoint to have eight stadiums that you can only use three months of the year?” he asked. “Of course not. So you need air-conditioning to make them viable long-term.”
There are costs, of course, both financial and environmental, and Ghani and Qatari officials will not disclose them. Some estimates have the eight stadiums costing a total of $6.5 billion, a price that does not include the human cost in lives lost and chronic health problems for the low-paid migrant workers who built them.
Oil and natural gas have made Qatar rich over the past half-century, and the World Cup is part of a coming-out spending spree. Skyscrapers, malls, luxury hotels and apartment buildings, a new airport and subway network — all drenched in air-conditioning, of course — have sprouted, Oz-like, improbably in this place.
There is little life here without air-conditioning. The city hums with the sound of it.
Ahead of the World Cup, some critics have focused on the stadiums. Seven new ones? Air-conditioned? Outdoors? Oh, the excess. Oh, the environment.
Ghani has heard the critics, including the climate concerns. More than half of Qatar’s electrical output goes toward air-conditioning, and while FIFA’s analysis claimed that the World Cup could be carbon neutral, critics doubt that claim, citing everything from new construction in the past decade to the thousands of flights in and out of Qatar during the tournament.
Ghani and World Cup organizers have declined to provide costs or data on the stadiums or the cooling systems.
For 13 years, working mostly in these university labs, Ghani has greeted his task as a mechanical-engineering puzzle — how to keep teams of soccer players, and the tens of thousands of fans assembled to watch them, cool in a place routinely with triple-digit temperatures, as efficiently and unobtrusively as possible.
His quest got attention. A reporter dubbed him Dr. Cool. He does not refer to himself that way.
‘A Nice Thermal Experience’
The overriding concept is simple science: Warm air rises, cool air falls.
Ghani did not need to cool the entire volume of the stadium — just the six feet or so above the ground where athletes played and in the sloping stands where people sat. Apply cool air down low, he figured, straight to the field (for the players) or to each row of seats (for the fans).
In theory, the cool air should sit right there, like a comforting blanket.
He needed to limit the variables that might puncture that cool layer, especially hot air. Each stadium was designed with a permanent white canopy to shield most spectators from sunlight most times of the day, but the canopies left ring-shaped or field-shaped holes to the sky.
The holes let hot air escape. They also let hot air enter.
For Ghani, chilling a stadium would be like trying to keep the inside of his Porsche cool while driving around Doha with the sunroof open — if his car held nearly 90,000 people, the capacity of Lusail Stadium, where the World Cup final will be played on Sunday.
Ghani uses the car analogy a lot. How would he generate enough cold air for each stadium? It is not unlike the closed system of a car radiator, he said.
There is a giant water tank, hundreds of thousands of gallons, hidden outside the stadium, out of view. Instead of coolant, stadiums use cold water to cool the air.
On the nights before games (more efficient than during the heat of the day), water in the tank is cooled to 5 degrees Celsius (41 Fahrenheit), Ghani said. The energy comes from a solar farm outside Doha, he said.
“I have only two pumps,” Ghani said. “One takes the chilled water to the stadium, and we have a lot of heat exchangers, like the car radiators, under the bleachers. Air is pulled from the stadium to the radiator with the cold water inside, and then back to the stadium.”
When it came to delivering cool air, Ghani wanted subtlety. He did not want the airplane method of delivering cool air: an in-your-face blast through a nozzle.
Under the seats and bleachers are specially designed vents meant to slow or diffuse the rush of air. Hundreds of thousands of them were produced. Cool air spills out more than it blows out. Most fans do not notice it on the back of their legs.
Not everyone gets the same treatment. The system has sensors and infrared cameras to make in-game adjustments and steer more cool air into different places.
An empty stadium heats up quickly from the body heat of thousands of fans. During day games, the sun shifts from one section to another. A few rows at the top of a section suddenly show up as warmer than the ones below. A humid day can feel warmer than a dry one, so the vents are adjusted accordingly.
“It’s an automated system, singing and dancing,” Ghani said.
Daytime temperatures during the World Cup have reached into the 90s, with evenings in the high 70s. From Nov. 22 to Dec. 2, there were four games a day, usually at 1, 4, 7 and 10 p.m. local time.
Stadium comfort — among the biggest concerns for this World Cup not long ago — has not been a story line.
“When I saw Saudi and Argentina, it really hit me,” Ghani said the day after the teams played at Lusail Stadium during the group stage. “I was designing for 80,000 people, but I never saw them. Then I saw everyone coming out of the stadium afterward and I was like, ‘Bloody hell! All those people were there, having a nice thermal experience.”
Not everyone has been impressed. A Brazilian player complained about air-conditioning making his team sick, and others have complained of being too hot or too cold.
At an afternoon game between Wales and Iran at Ahmad bin Ali Stadium, with the temperature at about 90, Welsh fans on one end stood throughout the match, squinting and sweating in a spot of sunshine. Some hid from the sun under Welsh flags, while others were given free visors to wear.
At halftime, most sought comfort in the cool shade of the concourse. A fan named Gareth Davies and his friends from Cardiff debated whether they had felt any cooler than usual. One man joked that maybe it was not news: “Pasty Wales fans, getting hot in the sun,” he said.
They wondered if two key factors had been overlooked: the sun and fans who chose to stand, maybe putting themselves out of reach of the under-seat vents.
“Someone got paid a lot for that design,” Davies said, “but it doesn’t seem to be making much of a difference.”
Cooling the future
Back at Qatar University, Ghani stood in a vast new building, not yet named, at the edge of the campus.
It is a gift, he said, from Qatari officials for the work on the stadiums. It will house his office and all the various research labs devoted to air-conditioning.
“Cooling is increasingly important for Qatar and this region,” Ghani said. “So that’s part of the legacy, too. We’re planning to make this a regional center for building physics.”
The focus on Qatar’s air-conditioned stadiums seemed to surprise him. Outlets from around the world, from Time to Scientific American, dived into the topic.
Think of all the massive, air-filled and roof-covered buildings across the globe’s hot spots: airport terminals, malls, warehouses, convention halls, indoor stadiums in places like Texas and Arizona that are stifling in the summer. They all have air-conditioning, he said, and not always efficient air-conditioning, sometimes working nonstop to cool far more voluminous chambers than the seating area or the field surface of a stadium once in a while.
To Ghani, there are bigger debates to have, about air-conditioning’s place in the world, and what cooling the air means for greenhouse gases or electric grids or even our relationships with the outdoors.
But he does wonder about future World Cups, including the 2026 tournament that the United States, Mexico and Canada will host. How “neutral” will players and fans feel in midsummer in outdoor stadiums in places like Miami, Kansas City, Philadelphia or the three host cities in Mexico?
And what about all of the World Cups after that, or the Olympics or any other major events that rely on outdoor stadiums as the planet continues getting warmer? If we want these games are to be played, comfortably and safely, in the time and places we want, Ghani said, we need to think about these things.
He positioned a scale replica of Al Janoub Stadium, detailed to every cantilever and ripple, in the wind tunnel, which had just been moved and reassembled in the new research building.
Ghani wanted to show how he and other researchers analyzed every stadium in the quest to beat the heat.
One of his assistants went to flip the switch. Nothing happened. Maybe a blown fuse. It would take a few days to track down an electrician.
No sweat. The new building itself was perfectly cool. Somewhere, an air-conditioner hummed.