Abstract The study presented in this paper is a continuation of small-scale passive solar wall module testing to evaluate: 1) the impact of phase change material embedded in building envelope on indoor air temperature in comparison to reference wall insulated with mineral wool 2) the impact of Fresnel lens on heat transfer processes in designed module compared to PMMA acrylic glass. Six different solar wall modules and a reference wall module were built and tested in a laboratory under controlled conditions. Compared to previous studies, changes in the experimental setup were made - solar radiation intensified, simulated outdoor temperature adjusted. The study shows explicitly the phase change melting processes in different modules tested, describing the differences between modules and impact of Fresnel lenses and insulation solutions. Room temperature with solar wall modules after the full cycle of charging and discharging latent and sensible energy (24 h) is higher than in the reference wall. Two of 3 of the proposed solar wall modules with Fresnel lens are more effective than modules with PMMA.