Qatar is fast growing towards becoming the hottest place on Earth because of a number of reasons, including but not limited to its geographical location near the Persian Gulf, the high levels of carbon dioxide emissions per capita and rapid construction of more avant-garde super skyscrapers.
The Supreme Committee for Delivery and Legacy (SC) -- responsible for overseeing the preparations of the FIFA World Cup in the country -- knew outbidding other nations with more experience in organising international sporting tournaments and securing hosting rights for the quadrennial showpiece in a country, which once recorded 50.4 degree Celsius temperature, would be a tough task. It had to do something amazing; in line with its slogan for the 2022 WC now - ‘Expect Amazing’.
This is when Dr. Saud Abdul-Aziz Abdul-Ghani, a professor at Qatar University, came to the rescue. An expert on the topic of engineering in air-conditioning, Dr. Abdul-Ghani was tasked with exploring a sustainable mechanism to negate the desert heat in the Middle East nation. After extensive research and testing, Abdul-Ghani first created a solar-powered cooling helmet for all the workers, who would have to toil in the arid conditions, before moving on to develop plans for outdoor air-conditioning systems in seven of the eight venues.
Explaining the mechanism, he said, “Inside it is like a micro bubble. If outside air is 52 degree (Celsius), I can provide 22 in the stadium. No problem.”
He then went on to compare open stadiums to a fish tank with oil on top. “Hot air is lighter than cold air. So, it will always stay up while the bottom will have cold air. We recycle that cold air. So, although it is an open space, it acts like a closed space. It is like oil and water. You are sitting in this stadium like a fish in water and will never switch to the oil part. We close all service doors while testing the kit and build a small layer of cold air at the bottom. The hot air above is like oil but we keep recycling the cold air so that you never move to the oil or the hot air part. The measure of our success is we minimise the mixing of the hot air with cold air.”
Incorporating the system at the Khalifa International Stadium proved to be the most challenging because unlike other venues which had to be built from scratch, this venue on Al Waab Street was built in 1976. The cornerstone of Qatar’s rich sporting culture, the arena has previously hosted the Asian Games in 2006, 2011 AFC Asian Cup, a few matches of the FIFA Club World Cup 2019 and the World Athletics Championships in the same year, among others.
“We have under-seat vents in stadiums like Lusail. That is better. In Khalifa, we have nozzles which throw air from a higher level. The cost of maintenance, therefore, goes up a little. The vents couldn’t be constructed here keeping in mind the structural implications breaking of old stairs might have had,” he said.
The 40,000-seater Khalifa stadium has 2,013 nozzles that push cool air across the tiers and onto the pitch. “The tunnels have big-slated winders which recycle the air. We pump the air into this big void but we suck it back, re-cool it and push it back out again. We do it so that the loads are smaller. The whole mechanical packages involved in cooling cost no more than 10 per cent of the whole budget,” he explained.
The coolers were first tested on a 35,000-strong crowd in attendance for the 2017 Emir Cup final. Abdul-Ghani said, “What we have done in Khalifa is better than moving about with a temperature sensor. We wanted to see how people perceive normal comfort and weather changes. Everybody had to fill in a small survey on their phones to describe their clothes, age, gender, where they are sitting and what they feel on a scale ranging from very hot, hot, neutral to cold and very cold. Then we monitored the input from our computer room and we’ve done the commissioning of the stadium on that basis.”
The artificial cooling technology also doubles up as a filtration system, informed Abdul-Ghani. “If there is dust in the air, we take it all away along with pollen and suspended particles. So, we purify the air as well. The mechanism is the same as it happens in a car. There are filters. When we soak in the outside air, it goes through a filter similar to a sieve with very small holes. The dirt particles get trapped with only clean air getting to pass through.”
There were a few earlier reports of the stadiums getting cooler than required. Abdul-Ghani, however, explained how this may have been only a one-off occurrence. “Our stadiums overcooled for one reason. These were made for a big heat load and during COVID-19 fans were not allowed so maybe the players felt a little bit cold. Actually, we have the best controlled system. For players we don’t measure temperature, we measure thermal stress - the ability of the skin to provide sweat that evaporates,” he said.
( The writer is in Qatar on an invitation by the Supreme Committee for Delivery & Legacy )