Qatar World Cup: Is installing air conditioners outdoors just a way of being rich? It's not that simple!

The quadrennial World Cup is being held in the Middle Eastern country of Qatar.

Unlike in the past, this time the word "hot" is not only a description of the intense competition itself, but also an objective description of the hot climate where the competition is held.

Qatar has a tropical desert climate, with only two seasons throughout the year: summer and winter.

The summer temperature here can reach 43°C, which is totally unsuitable for hosting football matches, so the 22nd World Cup was moved to winter for the first time.

But even in winter, that is, now, the maximum temperature here exceeds 30℃ every day.

Image source: Internet

In order to maintain a comfortable temperature in the stadium and prevent athletes and spectators from suffering from heatstroke in this "hot" environment, the organizers adopted a "bold" cooling method - "air conditioning".

At first glance, this may sound like a waste of electricity and not environmentally friendly, but don't jump to conclusions. You have to know that in order to save energy and enjoy comfortable "air conditioning", the people there have worked hard.

01

Consider cooling from the appearance

In order to welcome the 2022 World Cup, Qatar has mobilized a total of 8 large stadiums across the country, 7 of which are newly built and 1 is renovated.

Except for one stadium near the sea that can use natural ventilation and does not require cooling, the rest of the stadiums are equipped with air-conditioning systems.

The key figure in these air conditioning systems is a professor at Qatar University’s College of Engineering: Dr. Saud Abdulaziz Abdul Ghani, nicknamed “Dr. Cool” [1].

This is “Dr. Cold” Saud Abdul Ghani. Image source: Reference [1]

If you want to cool down an open-air stadium, you have to reduce the amount of solar radiation it receives as much as possible and retain the cold air inside the stadium, which requires starting with the design of the stadium's shape.

On the one hand, Dr. Leng’s team used computer software to simulate the thermal environment inside buildings of different shapes;

On the other hand, 3D printing technology was used to make a model of the stadium and placed in a wind tunnel for aerodynamic testing to adjust the size, height and shape of the stadium.

The final result is that each of the stadiums for the World Cup is shaped like an "air conditioning bubble", and the top openings are not designed to be too open, but slightly contracted.

While reducing the entry of hot air, it also reduces the escape of cold air inside, and casts as much shadow as possible on the stand area to block the scorching sun.

Some venues are also equipped with retractable roofs that can adjust the amount of light entering according to the weather, and the roof can be closed directly in case of bad weather[2].

Qatar World Cup venues, except for the movable 974 stadium, all other stadiums are equipped with "robust" cooling systems. Image source: StadiumDB.com, a stadium database website, Chinese translation: Science Popularization China

In addition, the tops of the venues are mostly made of light-colored materials to maximize the reflection of solar radiation and avoid absorbing excessive heat.

You may be familiar with the fact that dark-colored clothes absorb more heat than light-colored clothes.

So even the Al-Bayt Stadium, which was originally inspired by the traditional black tents of nomadic people, eventually changed its black roof to white.

Don’t underestimate this measure; this simple change can reduce the internal temperature of the stadium by 5°C! [1]

02

Internally, use "local cooling"

In order to achieve the goals of comfort and energy saving, the next step is to further reduce the area that needs to be cooled. After all, there is no need to cool the entire stadium, only the area where the audience seats and athletes are located (about two meters above the ground) needs to be cooled.

"Dr. Leng" calls it targeted or spot cooling - "targeted cooling" or "local cooling."

The purified and cooled air is then delivered to the people through grilles under the seats in the stands and large nozzles around the stadium.

The turbid exhaust gas is extracted and recycled through the air circulation system, re-cooled and filtered, and then re-sent in, and the cycle repeats itself.

By simply turning on the air conditioning system two hours before the game, spectators and players can experience the exciting event in a cool and comfortable environment of around 24°C.

Since cool air is denser, it stays low. This way of recycling the cooled air is more energy-efficient than sucking in hot, stuffy air directly from the outside.

Cool breeze blows from under the seats in the stands of Al Janoub Stadium. Image source: thenationalnews.com

So how is this cooling air produced?

It relies on the stadium's new cooling system.

Unlike the familiar household air conditioning systems, this system can be driven by solar energy and uses circulating water as a medium to cool the water to 7°C and store it to cool the air in the stadium.

"Dr. Leng" said that the energy consumed by this new air-conditioning system to cool the sports field is only 40% of the energy consumed by using conventional air-conditioning to cool a shopping mall of the same size.

If all electricity is from solar farms, its carbon emissions can be greatly reduced.

From the actual operation results, this system shows a strong cooling effect, sometimes even a little too strong, causing fans to have to bring an extra coat to watch the game.

03

Open air conditioning blows on the pedestrian street

In addition to cooling the stadium, this new air-conditioning system has also been extended to other public buildings in Qatar.

Recently, some enthusiastic netizens discovered that there are air-conditioning vents on the ground of Qatar’s pedestrian street, which continuously supply cool air to the street.

At least the gymnasium has a roof. Turning on the air conditioner in such an open space like the street is just like a math problem we did when we were kids:

Fill the swimming pool with water on one side and drain it on the other side! Is it true that you can be so willful just because you have money?

The place with air conditioning on the streets that netizens are hotly discussing is Katara Plaza in Katara Cultural Village, a famous tourist attraction in Doha, the capital of Qatar.

The entire project covers an area of ​​38,000 square meters and opened in 2016. It is the world's first commercial shopping mall to use open air conditioning[3].

The dark strips on the ground are the air-conditioning outlets. Image source: timeoutdoha.com

As the local high-end commercial district, the streets and buildings here are beautifully designed, but the hot weather makes people reluctant to go shopping.

In order to improve the utilization rate of street space, the design team worked with technical experts, combined with the experience of stadium air-conditioning systems, and also used technical means such as computer simulation to tailor a set of "active and passive combination" outdoor air-conditioning system for the project.

04

Green building technology in air conditioning

Wait, what is "active and passive combination"? What are passive and active? This is about a pair of technical routes commonly used in the field of green buildings - "passive design" and "active system".

Simply put, the strategy of improving building performance by designing building components and selecting building materials and utilizing local natural conditions such as lighting, ventilation, and evaporation is called "passive design."

The strategy of improving building performance by installing high-performance, green and environmentally friendly mechanical and electrical equipment is called an "active system."

The latter can make up for the part that the former cannot regulate and further improve the environmental quality with the least energy.

Therefore, there is a saying in the field of green buildings: "Passive priority, active optimization", and this two-pronged approach is called "combination of active and passive".

Remember the stadium introduced at the beginning?

The design of the size, height, shape, sunshade components and other parts of the stadium is a passive design; while the new air-conditioning system installed in the stadium, which is solar-driven, locally cooled, and has cold air circulation and filtration, is an active system.

Katara Plaza also adopts a unique passive design.

It takes advantage of the relatively cool temperature underground and places the cooling system in the underground space for circulation and transportation. It is then paired with an efficient, clean energy-driven air-conditioning system, which can also achieve the effect of energy conservation and emission reduction.

The blue part in the picture is the air conditioning pipeline and air outlet. Image source: Qatar Design Consortium

05

Carbon neutrality is a long way to go

It can be seen from many reports that the money Qatar spent on this World Cup, whether it is the stadium or the commercial street, is astronomical, so netizens joked that "people with money can do whatever they want."

Indeed, the one-time investment in simulation, experimentation, material selection, equipment, etc. of green buildings seems to be significantly higher than that of general buildings.

But whether discussing the economic feasibility or environmental benefits of buildings, we have to look at the entire life cycle of the building rather than focusing on just one stage.

If the energy, resources, carbon emissions saved, the extra income gained (such as increased business hours, etc.), the income from resource recycling, etc. during the decades or even hundreds of years of operation of a green building are converted into money and the total account of the entire life cycle is calculated, then green buildings are not as expensive as you think.

Most studies suggest that the additional benefits generated over the life cycle of a green building will ultimately far outweigh the additional initial investment[4].

What is actually more difficult to balance than money is the impact of carbon emissions on the global climate.

Although the stadium air conditioning system provides a comfortable environment for athletes and tourists, this measure has also caused many people to worry about energy consumption and carbon emissions.

Abbas Chamseddine, a structural engineer at the Qatar World Cup Stadium, believes that the air-conditioning systems in World Cup stadiums will undoubtedly cause waste.

Even if it could provide some help during winter racing, outdoor air conditioning cooling systems are unlikely to become mainstream.[5]

Zeke Hausfather, a climate data scientist at Berkeley Earth, said: “Qatar is one of the fastest warming regions in the world outside the polar regions, and if we do not take action to reduce greenhouse gas emissions, other parts of the world may not escape a similar fate.”[6]

In fact, the organizers of this World Cup have long set the goal of hosting the first "carbon neutral" World Cup, and have indeed made efforts and innovations in many aspects such as architectural design, clean energy, green transportation, and resource recycling.

But overall, the carbon emissions from events cannot be underestimated.

You may not believe it, but according to the 2021 FIFA Qatar World Cup Greenhouse Gas Accounting Report, the largest part of carbon emissions in this World Cup does not come from air conditioning the stadium, nor even from the construction of the stadium, which has much greater carbon emissions.

It is estimated that the carbon emissions caused by building the stadiums only account for about a quarter of the total carbon emissions of the event.

So, what is the link that causes large amounts of carbon emissions and is not environmentally friendly?

The third is the travel of participants, spectators, staff and volunteers, especially long-distance international flights. It is estimated that carbon emissions from transportation account for about half of total carbon emissions[7].

Image source: Reference [7]

It seems that more efforts are needed to solve longer-term and larger-scale environmental problems.

As responsible consumers, where can each of us take action?

References:

[1] FIFA. Dr. Cool: The mastermind behind Qatar 2022's air-cooled stadiums [EB/OL].(2019-12-16)[2022-11-27] https://www.fifa.com/tournaments/mens/worldcup/qatar2022/news/dr-cool-the-mastermind-behind-qatar-2022-s-air-cooled-stadiums

[2] Qatar Foundation. Cooling technology used in Qatar's World Cup stadiums powered by QF research [EB/OL].(2022-03-21)[2022-11-27] https://www.qf.org.qa/stories/cooling-technology-used-in-qatars-world-cup-stadiums-powered-by-qf-research

[3] Hilson Moran. Katara Plaza [EB/OL].[2022-11-27] https://www.hilsonmoran.com/project/katara-plaza/

[4] Sun Tongyu, Liu Sha, Shi Wenbin. Future significance and implementation path of net zero energy buildings[J]. Architecture Technology, 2020(8):6.

[5] Ivana Hindi. Outdoor AC in Qatar: Reality or Pipe Dream? [EB/OL].(2015-03-24)[2022-11-27] https://stepfeed.com/outdoor-ac-in-qatar-reality-or-pipe-dream-1908

[6] Steven Mufson. Facing unbearable heat, Qatar has begun to air-condition the outdoors[EB/OL].(2019-10-16)[2022-11-27]

[7] FIFA World Cup 2022™. Greenhouse gas accounting report [EB/OL].(2015-03-24)[2022-11-27].https://www.qatar2022.qa/sites/default/files/2022-08/greenhouse-gas-accounting-report-en.pdf

Author: Wan Li, PhD in Architecture, Associate Research Fellow, School of Architecture, The Chinese University of Hong Kong

Review | Luo Zhigang Senior Industrial Technology Engineer, Data Center Research Institute, China Academy of Building Research

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