• Tixier, Nicolas
• Broggini, Filippo
• Beysens, Daniel
• Ouazzani, Jalil
• Milimouk-Melnytchouk, Iryna

Abstract

Dew is a natural phenomenon that occurs under particular weatherconditions (clear nocturnal sky, humid air, low wind) and on a surfacespecially designed for this purpose (high radiative cooling properties,special architectural design). Depending on the weather conditions andthe surface characteristics, the water yield can give up to 0.7 litres persquare meter and per night. Although the collection of rain water on roof turns out to be relativelysimple, dew harvesting needs a more sophisticated architectural designto be efficient. Then this project aims at testing roof designs that improvedew water recovery by modulating two major parameters related to itsrecovery: (i) surface quality (strong emissivity, wetting character, low heatcapacity), (ii) the shape of the roof (slopes, orientations with respect todominant wind, gravity-induced water flow, etc.). A first step was the exploration of urban structures/sculptures, whichwas carried out by numerical works and small scale modelling (workshopheld on December, 2008). In a second time (April, 2008), three roofprototypes on scale 1:1 of approximately 4m 2 each are constructed andtested. These prototypes are designed with metals (sets of oriented planesurfaces), resins (modular plays of crooked surfaces) and textile (stretchedstructures). These multi-disciplinary researches on dew water harvesting aims at asynergy between partners of different disciplines and statutes: physicists,architect-designers, industrialists and teachers. They can apply to all thescales of the habitat, from garden cabins to roofs of building, car parks orsupermarkets. It finds its interest in many regions of the world, in arid orsemi arid environment and also European countries. (It is worth notingthat the surface coating used to improve dew collection also providesnatural cooling during the day.). We propose on conclusion of this paper, a pavilion project with on of this system.

Topics

• impedance spectroscopy
• surface
• resin