Radiant Panels

Solution A) is a monolithic panel fabricated by coupling a high density geopolymer layer (HDG) 6-8 mm thick produced by a casting process to an insulating EPS layer 30-50 mm thick with embedded piping diam 10mm). The HDG can incorporate at least 40-50% in weight of selected CDW. Inorganic waste will be selected having the highest thermal conductivity (concrete, and aggregates). A total weight of the panels of about 18kg/m2, which is only slightly higher compared to state of the art gypsum panels (16-17 kg/m2) can be obtained. Prototypes of these panel without incorporation of CDW have been already produced, evaluated by numeric simulations and tested in a climatic chamber to determine their radiating efficiency for cooling and heating. The mechanical properties of the HDG layer have been determined. A compressive strength up to σc =90 MPa and flexural strength up to σf =16 MPa have been obtained which are much higher than mechanical properties of fibre-reinforced plasterboards σc =25 MPa, σf = 5.8 MPa. The thermal conductivity measured of HDG was λ=0,7 Wm-1K-1 compared to λ=0.25 Wm-1K-1 for gypsum. The thermal efficiency of a radiant ceiling radiating panel with 50×100 cm2 area has been measured according to standards under ambient conditions for heating (Tambient=20oC) and cooling (Tambient=26oC). The measured heat flux extracted (cooling) or supplied (heating) to the ambient was compared with simulations of the geopolymer panels and of traditional gypsum/plasterboard panels under the same boundary conditions and pipe-tube distances.

The measured heat fluxes are in reasonable agreement with the simulations and show a higher radiating efficiency of the proposed technology with respect to comparable traditional plasterboard radiant panels by 32% for heating and 14 % for cooling. Therefore a decrease of water temperature by 3°C for heating can be expected thereby resulting an improvement of 3-4% in the COP of the heat pump.

Solution B) A second type of panel will be developed that will allow more easy disassembly of the EPS layer by bonding it reversibly to the EPS panel. To this purpose the piping will be surrounded by a high density geopolymer outer layer 6-8 mm thick (HDG) and a wood-geopolymer inner layer 10-15 mm thick (WGP) to provide a flat interface for reversible and seamless coupling (velcro or other) of the radiative part of the panel with flat commercial EPS panel. The weight of these panels will be 20-30 kg/m2. While higher than for state of the art gypsum panels (16-17 kg/m2) the panels can be still fabricated with weights compatible with installation requirements (<25 kg/m2). The slightly higher weight should be balanced by the easy recycling of these panels provided by the simple disassembly of the insulating EPS layer from the radiative geopolymeric part thereby addressing the negative recycling aspects of plasterboard radiative panels. The thermal conductivity of the WGP layer will be in the range λ=0,2- 0,3 Wm-1K-1 which will influence the radiative performance of the panels increasing the insulation and allowing to reduce the EPS (or other) thickness.