Thermal optimization of 3D-printed block – Hot Box and heat flow meter experimental analysis

In Europe, the buildings sector is a significant energy consumer, second only to the transport sector and, among the various industrial sectors, it has experienced poor technological progress, which is still strongly based on manual work. For this reason, it is considered a low-tech sector. Therefore, searching for new construction techniques that can speed up processes, reduce waste material and ensure customization of built elements is crucial. Additive manufacturing represents a promising and increasingly developing approach worldwide, although less attention is paid to studying the features of 3D-printed building components in the thermal field. In this paper, the thermal performance of a 3D-printed block is studied. The block is made up of recyclable plastic material, i.e., polylactic acid (PLA), with an internal honeycomb composition. The performance was studied experimentally using a specially made Hot Box together with heat flow meter sensors and infrared thermography, assuming different orientations of the air cavities. The experimental campaigns were carried out by imposing steady-state, repeatable, and controlled conditions. The results obtained showed that the different orientation of the air cavities determines effects on heat transfer phenomena, with reductions of up to 7% in terms of thermal transmittance. In fact, while the transmittance value of the block with the vertical cavities resulted equal to 1.22 ± 0.04 W/m2K, the U-value of the block with horizontal cavities was 1.13 ± 0.04 W/m2K.