The development of an innovative radiant heating system, made for room temperature control, requires extended laboratory and numerical analysis. The multilayered wooden structure design in particular is a challenging aspect due to thermal and hygric transport processes: This article focuses on a thermal optimization process, which aims at increasing the heating performance of first panel prototypes. In a first step, a numerical analysis was performed evaluating design parameters, which contribute to an efficient heating curve of the system. Subsequently, prototypes were defined and produced in pilot plant scale. Comprehensive measurements, performed within a climate chamber, focused on an investigation of hygrothermal transport processes within the wooden panel. Surface temperatures were measured by means of an infrared thermographic camera and temperature sensors. Furthermore, surface heat flux was recorded and relative humidity was measured at defined positions within the panel's cross section. The obtained data sets contribute to a calibrated numerical model, which takes into account anisotropic material properties. Additionally, dimensional stability was analyzed within a double climatic chamber. An optimized panel variant is found to have an average surface temperature 3.4 degrees C higher than a first prototype. Additionally, considering anisotropic material properties within a numerical model allows for the optimization of energy transport processes. (C) 2016 Elsevier B.V. All rights reserved.