The 3D Printing Potential for Heat Flow Optimization: Influence of Block Geometries on Heat Transfer Processes

Abstract

The building envelope is a crucial element in the regulation of thermal energy in the indoor environment, from which comfortable living inevitably depends. Designing a low-dispersion envelope represents a fundamental strategy to minimize the energy demand and HVAC systems’ consumption. To this end, the need to select suitable insulation has become increasingly important, and the search for new solutions is constantly evolving. This justifies the great interest in the study of energy-efficient and sustainable insulation materials that are able to provide the low thermal transmittance values of multilayer components. To date, 3D printing has experienced a growing popularity for the research of alternative building materials (e.g., concrete). Conversely, it still appears to be very uncommon for the research of purely energy-efficient solutions. The aim of this work is to compare the thermal performance of three 3D-printed PLA (polylactic acid) blocks, characterized by different internal geometries and air cavities: (i) a multi-row structure; (ii) a square structure; (iii) a honeycomb structure. The study was conducted theoretically, with two-dimensional heat transfer modeling, and experimentally, by means of a heat flow meter and infrared thermography. The results showed that the configurations of the 3D-printed blocks reduced the flow of heat exchange. In addition, as the complexity of the blocks’ internal structure increased, a heat flow reduction could be observed. In particular, the honeycomb structure showed a better behavior than the other two blocks did, with an experimental transmittance value that was equal to 1.22 ± 0.04 W/m2K. This behavior, which was mainly due to an attenuation of convective and radiative internal heat exchanges, suggests that the 3D printing has great potential in this field.