One way of keeping people cool in hot climates is to spray a cool mist through which they can walk. Spraying mist continuously, however, can use a lot of water. A new installation called Personal Cloud reduces the amount of water used by detecting passersby and targeting mist at them only.
Personal Cloud was conceived by Italy's Carlo Ratti Associati architectural firm. The company explains that the evaporative cooling process it employs is more energy-efficient than air conditioning, but that by being more targeted at where the mist is sprayed, can be more efficient still.
"In traditional systems, a lot of energy and water are consumed by cooling outdoor spaces, even when these spaces are sparsely used," says Carlo Ratti in a press release. "In our project, we focus misting on people, which is considerably more energy efficient."
Personal Cloud comprises a swarm of tubes that hang down from a canopy, and from which mist is sprayed. The system uses ultrasonic sensors to detect when people move underneath them by measuring the time taken for an ultrasound signal to be sent and the echo received.
When a person is detected underneath specific sensors, hydro-valves and LED lights in the surrounding tubes are activated. This creates a personal cloud of mist around the individual that moves with them as they pass under the installation, and avoids the need to activate the whole installation in one go. The LEDs, meanwhile, create a backlit visual effect.
Personal Cloud was developed for and unveiled at the UAE Government Summit this week. Carlo Ratti tells Gizmag that plans to roll out the installation commercially will likely be developed in the near future.
The video below shows Personal Cloud in action.
Source: Carlo Ratti Associati
Not competitive to AC indoors with a controlled climate.
They aren't nearly this fancy but a system that mists based on your movement would have to analyze your path and "lead the target" which might not be very easy to do. If the nozzles only mist as you pass under them its sure to miss you unless you stand still.
Just don't insert any body parts into the vertical 'spike' of water these things create above the transducer, especially not at the top where the water is being ripped apart by the focused ultrasound. I know someone who did that just for an instant and he got a little painful bruise on a finger, which took a long time to heal.