The city wants to deal with “heat islands” with a permanently installed fog machine. When you look in Zurich West, however, there is absolutely no sign of cooling down.
Cloud of fog over the Turbinenplatz: A cooling effect is not noticeable at the inauguration on Tuesday.
A cloud for the city of Zurich: This news throws high waves. The media interest in the inauguration on Tuesday was enormous, even a correspondent from a Ticino medium came. An artificially generated cloud of fog is presented, which is intended to provide cooling on hot days on the Turbinenplatz in Zurich West. Memories of the walk-in cloud at Expo 02 are awakened – a steel construction twenty meters high in Lake Neuchâtel with 31,400 stainless steel nozzles.
The NZZ wrote at the time: “Anyone who strolls through the mounds of the Arteplage in Yverdon-les-Bains is reminded of prehistoric tumuli and dolmens. If you come to the lake from this direction in wet weather, you will see a small island rising out of the fog in front of you. From this perspective, the cloud looks like the mystical Avalon. Two fiberglass walkways lead in.»
“Like the mystical Avalon”: “Le nuage” at Expo 02 in Yverdon.
Anyone who looks at Zurich’s “cloud” with these words in their ears will be disappointed: four wooden poles, between them steel cables that carry an aluminum ring – very functional. There are 180 nozzles that produce a thin spray mist. The ring looks a bit lost on the large Turbinenplatz in Zürich-West. You definitely can’t walk in a cloud here. The somewhat sought-after name “Alto Zürrus”, which the object was given in reference to the cirrus cloud, cannot hide this.
The «cloud» turns on automatically
The Neuchâtel cloud was an art project – the much smaller Zurich sister serves a more mundane purpose. It’s about overheating in cities as a result of climate change. It must be assumed that the number of hot days will double to 44 per year by 2040, says the new city councilor and civil engineering director Simone Brander (SP) on Tuesday. Zurich cannot contribute that much in the fight against climate change (although one should not be left behind). But there is a lot that can be done locally to reduce the heat.
As soon as the thermometer rises to 30 degrees, the “cloud” switches on automatically. The energy consumption is roughly the same as that of a vacuum cleaner. 7.5 liters of water are sprayed per minute. That’s 100,000 liters a year – assuming the ring is active for 44 days. This is about a tenth of the consumption of a drinking fountain in the city of Zurich.
Drinking water is sprayed. Something else is not possible for hygienic reasons, according to Grün Stadt Zürich. Some people will ask themselves whether it is opportune to blow drinking water into the air in times of water shortages in southern Europe. Zurich likes to see itself as a role model for other cities when it comes to environmental issues – this project is unlikely to be suitable for that.
“Alto Zürrus” is a pilot project and will run from July 2022 to September 2024. The idea for this came from an employee of Grün Stadt Zürich, who “won” the implementation in an internal city competition. Grün Stadt Zürich estimates the cost of the project at CHF 140,000. This includes the costs for the scientific support: It is measured exactly how big the effect actually is.
The expectations are high. “People can stay there and enjoy the cool breeze without getting wet,” writes Grün Stadt Zürich. The water particles would immediately evaporate and extract heat from the surrounding air. The ambient air cools down by up to 10 degrees Celsius.
This may be possible under laboratory conditions – but when you look at it on Tuesday afternoon, at 27 degrees, there is no sign of a cooling effect at all. The space is probably too large or the ring too small for an effect on the surrounding air to be noticeable. And the cooling spray doesn’t reach the floor either, the ring is simply too high for that.
In contrast to a similar project in Bellinzona, the decision in Zurich was not to have a roof over the “cloud”. There are no benches or other places to sit here, the ring hangs over the bare asphalt. The Turbinenplatz is generally not very busy, and there are only a few residents here.
This is special because, according to the exercise facility, the city wants to find out how popular it is with acceptance. However, it is doubtful that there will be large numbers of them under the pseudo cloud. Grün Stadt Zürich justified the choice of location by saying that other heat reduction measures would also be tested on the Turbinenplatz. It is also one of the hottest places in Zurich.
On Tuesday, Simone Brander left open whether the pilot project would be followed by further “clouds”. She never tires of emphasizing that the “cloud” is just one of many means. Among other things, trees were planted on the Turbinenplatz, but it took a while until they were big enough to provide shade. The “cloud” is an “immediate measure”.
Brander says trees are unbeatable when it comes to heat reduction. Anyone who has spent a few minutes in the blazing sun, with the cooling spray at an unreachable height above them, is inclined to agree.