Influence of gap size between aluminium radiant sheets on the efficiency of lightweight floor heating

Abstract

For environmental and economic reasons, it is necessary to search for heating systems solutions that are efficient and provide thermal comfort at a low investment cost. In this study, the optimum gap between aluminium radiant sheets in lightweight floor heating is determined, ensuring high system efficiency and low material consumption. Numerical calculations were performed using the ANSYS. The structures analysed consist of thermal insulation covered with a 0.3 mm thick aluminium sheet, wood-like board and ceramic tiles or panels. The average surface temperature and the temperature amplitude are determined for the construction with no gap between the sheets and with gaps of 10, 20, 30 and 40 mm. Increasing the gap size results in a decrease in the surface temperature and heat flux and an increase in temperature amplitude. For a 10–20 mm gap, the decrease in temperature (<0.47 K), relative heat flux drop (<4.4%) and increase in surface temperature amplitude (<1K) can be considered negligible at a water temperature of 25–40°C, pipe spacing of 0.075–0.150 m and the thermal resistance of the layers above the pipes ≤0.118 m2K/W. A gap of 10–20 mm compared to no gap reduces aluminium consumption, which is environmentally friendly while ensuring high system efficiency.