Energy-efficient structures and technologies in additive construction

The object of research is the improvement of the thermal resistance of the buildings’ enclosing structures created with the use of additive technologies. Method. Numerical research, experimental investigations, and secondary analysis of existing data on heat conductance of 3D printed building envelopes were used to investigate the energy efficiency of the building envelopes. The energy efficiency of 3D-printed buildings is based on two main factors: the efficiency of engineering systems and the efficiency of thermal protection. The heat transfer coefficient (U-value) of a 3D-printed wall is influenced by the internal configuration of the wall and by the materials used. The influence of the wall configuration on the U-value of the structure and the efficiency of the insulating material was evaluated based on numerical calculations and CFD modeling data. These two approaches were compared. It was detected that the wall configuration with zigzag internal stiffening diaphragms is the most efficient. The presence of mineral wool insulation in the wall structure increases the heat transfer resistance of the wall, but the efficiency of thermal insulation also depends on the wall configuration. Different wall configurations were investigated, and the change in U-values varied from 32% to 64% when the insulation was considered. Results. The results of empirical calculations of U-values for insulated walls showed extremely low results compared to the U-values obtained from CFD modeling. The high divergence of the results makes it impossible to use the empirical approach to calculate U-values for complex walls. Since 3D-printed walls are mostly made of concrete, the possibility of reducing the thermal conductivity of the concrete was investigated. Aerogel powder in the amount of 15% by volume was added to the concrete mixture. Heat conductivity measures of the manufactured samples showed a 25% reduction average in the heat conductivity of the concrete specimens.