Manufacturing and experimental analysis of a dew-point indirect evaporative cooler using fused deposition modelling 3D printing and polymeric materials

Abstract

Evaporative cooling (EC) is an interesting alternative for reducing energy consumption and CO2 emission associated with the cooling of building. In the present work, a prototype of an innovative dew-point indirect evaporative cooler (DIEC) was manufactured by additive manufacturing technology. This prototype was made up of two types of materials: (a) one porous, with high water absorption capacity, polyvinyl alcohol (PVA) with felt, and therefore, high capacity of generate EC; and (b) another with high hydrophobic properties, polylactic acid (PLA) with bronze. The materials were characterised in terms of thermal, water absorption properties and morphological properties. Prior to manufacturing, a design of experiments was conducted in order to find the optimal manufacturing parameters. The prototype was produced through an innovative process, based on the simultaneous use of two extruders, and the manufacture of a porous layer of felt by dissolving the PVA matrix where the felt was initially embedded. Finally, the energy performance of the prototype was experimentally analysed, reaching values of dew-point effectiveness up to 0.9 and energy efficiency ratio up to 22.74 at 45 °C outside dry bulb temperature. These results show that additive manufacturing is promising for developing competitive compact and highly energy efficient DIEC systems.