By Orlando Crowcroft
Who said cooling can’t be carbon neutral?
A lot of the criticism surrounding Qatar’s bid for the 2022 World Cup surrounded the heat, given that most of the games will be played during the country’s hottest months of the year.
The fact that Qatar planned to air condition its stadiums has also been subject to some scepticism, but as engineering giant Arup reveals, it is possible to keep football stadiums both cool and sustainable even in the country’s hottest months.
Arup designed a 500-seat, carbon-zero model stadium as a development platform to refine sustainable technologies for application across Qatar and potentially across all arid regions. The stadium was designed to demonstrate to FIFA that the harsh climate over the summer months is no longer a barrier to hosting global events.
The showcase is based on three key aspects: an exciting architecture and structure which develops traditional passive design ideas to a new energy-saving and comfortable architecture; photovoltaics that convert the energy of the sun into electricity and capturing and converting the sun’s heat into cooling for summertime air conditioning using under-seat supply.
The canopy roof, the first of its kind in the world, moves to provide cooling shade within the building and insulates against the hot sun in summer. In addition to protection from sun-light, the canopy can be positioned to protect from wind during match times and let spectators and players take advantage of natural ventilation. In hot conditions, the canopy can be closed in the run-up to an event to allow cooling to work at maximum efficiency, using cooling from the sun to cool down the volume ready for match time in the summer evenings, when it can be opened.
Meanwhile, the venues’ solar panels will operate year-round, continuously exporting electrical energy to the grid. On a match day, the higher electrical demand will bring electricity back into the facility from the grid. This electricity, together with generators using biofuels, provide robust and reliable power for both technical and general power, so the events are assured power during the World Cup. The amount of electricity generated in this way from the sun exceeds the amount of electricity imported for events over the year, making the facility zero carbon for electricity.
Next to the photovoltaic panels is an array of solar heat collectors, which have a series of motorised mirrors that track the sun, focusing the sun’s power onto collecting tubes which have hot water circulating in them. They collect this energy in the form of heat, which is converted into cooling for the Showcase environment, and electricity to supply lighting, power and other functions within the space. The solar energy heats water to 200C and is converted to cooling water by machines called absorption chillers.
The air-handling units supply this air to the area beneath the spectators seats. This cools the seating area and flows down to create cooling for the players. The surfaces of the Showcase are designed to remain cool throughout the match to help to stabilise the heat gains from lights and people. The maximum temperatures are below the guidelines by FIFA to avoid players suffering significant heat stress and also beat the ASHRAE comfort standards for spectators.
During the FIFA visit, with an outside temperature having reached 44 degrees only two hours earlier, the temperature on the pitch was recorded as 23 degrees. The stadium was instrumental in securing Qatar’s successful bid.For all the latest construction news from the UAE and Gulf countries, follow us on Twitter and Linkedin, like us on Facebook and subscribe to our YouTube page, which is updated daily.