On the applicability of atmospheric water harvesting technologies on building facades: A critical review

Abstract

The current climate emergency has already impacted life on Earth with increasingly extreme, prolonged, and frequent weather events. One of the most critical consequences is the progressive desertification of lands, leading to a scarcity of safe and sustainably sourced freshwater supplies. Water availability is entwined with regional economic and social benefits, as well as environmental and ecosystem security. Today, about 4.5 billion people have inadequate access to clean water, pushing to find alternative solutions for providing safe water to all. Localized atmospheric water harvesting (AWH) may represent an economical and efficient alternative, and some case studies already demonstrate its small-scale viability. Nonetheless, its large-scale applicability in urban environments and its related impacts and barriers are significantly under-explored.This paper proposes a systematic review of the main AWH technologies from the literature. It evaluates their potential for application on building façade components by identifying the technology readiness level (TRL) and undertaking a Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis. Results indicate that the currently available technologies, despite their infancy on the TRL scale, offer significant potential for application at the building scale. Future research should investigate the boundary conditions necessary for AWH technologies to work in urban environments to identify a roadmap for large-scale uptake from the construction industry.