The transformation of existing green wall technology to provide urban heat rejection infrastructure

Yale University, New Haven CT

Investigators

Abstract

1438564 (Felson). Green walls provide benefits that have fostered the growth of a new industry as they can passively moderate exterior wall surface temperatures and thereby reduce building heating and cooling loads, attenuate surface temperature variations and solar exposure that degrade exterior wall finishes, and provide ecosystem service benefits including air pollution and particulate removal, mitigation of urban heat island effects, and urban wildlife habitats. To date, these benefits do not offset the costs of green walls, and therefore, the market for green walls remains limited. This research will address problems that must be resolved to transform existing green wall technology into an active technology for process heat rejection (i.e., principally, here, for chilled water generation), and thereby expand the market to a wide range of applications from households to institutions and industry. The objective is to provide a sustainable alternative to wet cooling tower technology that maintains the benefits of existing green walls, employing their methods of construction and operation, while avoiding the shortcomings of wet cooling tower technologies (i.e., single use and contamination of cooling water). The investigators are targeting the creation of a green wall heat rejection technology with integrated water biofiltration capabilities and a mathematical transport model to simulate the thermal and biofiltration performance of the technology for experimental and design purposes. The performance of these "thermoGreenWallTM" (tGW) systems will be investigated through coordinated experimental and modeling methods using lab-scale tGW panels and full-scale prototypes and a tanks-in-series model developed by the PIs. The lab-scale tGW panels will be constructed as mesocosm experiments to systematically investigate plant/substrate compatibility/productivity (e.g., using a root area meter and destructive sampling for root biomass determination), plant health (e.g., using chlorophyll fluorescence), water biofiltration methods, performance, and interaction with plant/substrate systems, and heat rejection transport mechanisms and performance.