3.2.2. Khalifa Stadium, Doha, Qatar (2017)

Another example of a building using windcatchers as a cooling tool is the Khalifa Stadium, which was built for the FIFA 2022 World Cup in Qatar (Figure 38). The cooling system used by the fans is installed in cooling towers located more than 1 km away from the stadium. The cooled water is pumped from the towers into the stadium. There are 9 units in the NCR2610 fan, with a 26 ft diameter, and 10 blades with an airflow capacity of 433.4 m3/s [46].

**Figure 38.** Khalifa International Stadium showing the wind tower in the red square; adapted from [47].

The Khalifa International Stadium is the largest cooled outdoor stadium in the world. A system that works to reduce energy consumption was therefore used in this building. This system, called "urban refrigeration, "successfully keeps the players and the audience within the comfort range. In this system, refrigeration technology is 40% more sustainable than conventional techniques. This is made possible with the utilization of an energy center located one kilometer from the stadium. In this center, the cooled water is carried through a pipe to the venue. The cold water then arrives, cools the air, and then is pushed toward the center of the stadium, the playing field, and the seating areas to reach a total of about 500 vents dispersed around the stands. Moreover, because the cold air is denser, it remains

low near the ground; therefore, not all the hot air enters [46]. This is accomplished by the effect of buoyancy force, as discussed in the Introduction section of the paper.
