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A numerical parameter sensitivity analysis of the design parameters of the recently published solar selective thermal insulation system (SATIS) has been carried out to enhance its thermal and optical properties. It turned out that the insulation properties of SATIS can be effectively improved by reducing the length of the glass closure element. Increasing the area share of the light conducting elements (LCEs) and decreasing their length-to-diameter (L/D) ratio were identified as key parameters in order to increase the solar gain. Two SATIS variants were compared with the same wall insulation without SATIS in a yearly energetic performance assessment. The SATIS variant with 10 mm length of the closure element, 44.2% area share of LCE, as well as front and rear diameters of 12 mm/9 mm shows an 11.8% lower transmission heat loss over the heating period than the wall insulation without SATIS. A new methodology was developed to enable the implementation of the computed solar gains of SATIS in 1D simulation tools. The result is a radiant heat flow map for integration as a heat source in 1D simulation models. A comparison between the 1D and 3D models of the inside wall heat fluxes showed an integral yearly agreement of 98%.
Peter Steininger; Matthias Gaderer; Belal Dawoud. Assessment of the Annual Transmission Heat Loss Reduction of a Refurbished Existing Building with an Advanced Solar Selective Thermal Insulation System. Sustainability 2021, 13, 7336 .
AMA StylePeter Steininger, Matthias Gaderer, Belal Dawoud. Assessment of the Annual Transmission Heat Loss Reduction of a Refurbished Existing Building with an Advanced Solar Selective Thermal Insulation System. Sustainability. 2021; 13 (13):7336.
Chicago/Turabian StylePeter Steininger; Matthias Gaderer; Belal Dawoud. 2021. "Assessment of the Annual Transmission Heat Loss Reduction of a Refurbished Existing Building with an Advanced Solar Selective Thermal Insulation System." Sustainability 13, no. 13: 7336.
A newly-developed solar active thermal insulation system (SATIS) is introduced with the main objective to accomplish a highly-dependent total solar transmittance on the irradiation angle. SATIS is also designed to obtain the maximum transmittance at a prescribed design irradiation angle and to reduce it remarkably at higher irradiation angles. A purely mineral thermal insulation plaster with micro hollow glass spheres is applied to manufacture the investigated SATIS prototype. Light-conducting elements (LCEs) have been introduced into SATIS and suitable closing elements have been applied. The SATIS prototype has been investigated both experimentally and numerically. It turned out that the contributions of conduction, radiation and convection to the effective thermal conductivity of SATIS, without the closing elements (49
Peter Steininger; Matthias Gaderer; Oliver Steffens; Belal Dawoud. Experimental and Numerical Study on the Heat Transfer Characteristics of a Newly-Developed Solar Active Thermal Insulation System. Buildings 2021, 11, 123 .
AMA StylePeter Steininger, Matthias Gaderer, Oliver Steffens, Belal Dawoud. Experimental and Numerical Study on the Heat Transfer Characteristics of a Newly-Developed Solar Active Thermal Insulation System. Buildings. 2021; 11 (3):123.
Chicago/Turabian StylePeter Steininger; Matthias Gaderer; Oliver Steffens; Belal Dawoud. 2021. "Experimental and Numerical Study on the Heat Transfer Characteristics of a Newly-Developed Solar Active Thermal Insulation System." Buildings 11, no. 3: 123.
This communication introduces an experimental setup for investigating the effect of solar radiation on the reduction of transmission heat losses and the steady state thermal conductance of uninsulated and insulated multi-layer wall samples. The setup consists of two adjacent climatic chambers, which share a common wall, in which the multi-layer wall samples are mounted. A solar simulator is applied within the outdoor air climatic chamber, whose radiation spectrum and radiation intensity are approximately equivalent to those of the sun. The first tests have been carried out on a wall sample with a typical structure of existing buildings from the year 1930 in Germany. In addition, a high-performance insulating plaster layer has been applied on a basic test sample (with existing building structure) to replicate and assess the refurbished scenario. Furthermore, a numerical investigation on the transient heat transfer process is carried out by using the simulation software COMSOL Multiphysics®. The experimental results of both uninsulated and insulated wall samples are validated against 1D and 3D models. As seen, the uninsulated wall, whose thermal conductance was experimentally determined to be equal to 1.79 W/(m²K), absorbs a heat flux of 208 W/m² through its external wall surface over a period of 8 hours. A fraction of 9.8 % of the absorbed heat arrives as a gain on the internal wall and reduces the transmission heat losses by 11.7 % over a period of 55 hours. On the other hand, the thermal conductivity of the insulation layer of the refurbished wall sample with micro hollow glass spheres was estimated by a parameter estimation procedure using the 3D model and the obtained experimental data. Using the estimated thermal conductivity, a thermal conductance of 0.42 W/(m²K) has been obtained for the refurbished wall sample.
Peter Steininger; Matthias Gaderer; Belal Dawoud. Experimental and numerical study on the solar gain and heat loss of typical existing and refurbished German buildings. iCRBE Procedia 2020, 75 -93.
AMA StylePeter Steininger, Matthias Gaderer, Belal Dawoud. Experimental and numerical study on the solar gain and heat loss of typical existing and refurbished German buildings. iCRBE Procedia. 2020; ():75-93.
Chicago/Turabian StylePeter Steininger; Matthias Gaderer; Belal Dawoud. 2020. "Experimental and numerical study on the solar gain and heat loss of typical existing and refurbished German buildings." iCRBE Procedia , no. : 75-93.