Innovative evaporative cooling walls

In this chapter we will present the basics of evaporative cooling walls. Water evaporative cooling systems exploit the latent heat of evaporation of water to reduce sensible heat of air, and therefore its temperature. Based on this principle, both direct and indirect approaches can be developed. Their adoptionmay dramatically decrease (and sometimes even cancel) cooling loads in warm and hot seasons. So these walls are the best candidates for adoption inmild climates with relatively long summer seasons,where the use of highly insulatedwalls to limit heating loads may cause internal overheating in hot periods and make the indoors quite uncomfortable and unhealthy. Not only can this technology considerably decrease incoming cooling loads, which is beneficial during warm and hot seasons, but it also keeps high insulation standards against heat dispersion in winter. More specifically, evaporative cooling walls represent an example of a hybrid solution deriving from the combination of ventilated fac¸ades and water evaporative cavity walls. In this chapter we will look into this technology, starting with an overview of the state of the art, then going through the basics of evaporative cooling systems and, finally, focusing on the issue of evaporative cooling walls. In particular, Section 8.4 will be devoted to highlighting some important concepts that are useful for their design, and will describe the experience gained by the authors while working in this field. Likely future trends, suggested sources of information, and conclusions will end the chapter.