Radiant Panels

Solution A is a monolithic panel sizing 59.5 by 59.5 cm, compatible with the standard ceiling mounting systems. The panel is fabricated by coupling a high density geopolymer layer (HDG), produced by a casting process, to an insulating EPS layer with embedded piping. The geopolymer layer is 6 mm thick and contains 50% in weight of inorganic CDW. The insulating layer is 50 mm thick and the piping diameter is 9.9 mm. Each panel weights 7.6 kg (21 kg/m2) which is only slightly higher than the state of the art gypsum panels (16-17 kg/m2).

A key value to define the performance of the panels is the thermal conductivity. The measured thermal conductivity of the HDG is λ=0,77 Wm-1K-1 that is higher than the usual plasterboard value (around 0.25 Wm-1K-1).

The radiant panels have been evaluated, according to the current standards, to define their thermal performance inside a dedicated test room, with different ambient conditions for heating (room reference temperature equal to 20°C) and cooling (room reference temperature of 26°C). The measured heat flux extracted (cooling) or supplied (heating) to the ambient was also compared with simulations of the geopolymer panels and of traditional gypsum/plasterboard panels under the same boundary conditions and piping layout.

The measured heat fluxes are in good agreement with the simulations and show a higher thermal output of the proposed technology, with respect to comparable traditional plasterboard radiant panels, of almost 20% for cooling. This allows to feed the panels with higher water inlet temperature in summer and lower in winter, leading to an improvement of the efficiency in the generation system (such as heat pumps).

Solution B as the second type of panel was developed for wall applications, allowing an easier disassembly. Also this panel has a size of 59.5 by 59.5 cm2 but with a very low thickness of 21 mm. It can be used either reversibly bonded to an insulator sheet, such as EPS, or directly mounted on an already internally insulated wall. The panel consist in a 6mm thick outer dry HDG layer, in close contact with the embedded piping, and a 15mm thick rear wood geopolymer (WGP) layer. The thermal conductivity of the dry HDG layer is equal to 0,55 Wm-1K-1 while the one of the WGP is 0,27 Wm-1K-1 The panel weights 8.6 kg (24 kg/m2).

The thermal efficiency of the panels has been measured both in cooling and heating mode in wall configuration, obtaining good results.