A prototype facade element equipped with an integrated solar thermal collector and latent heat storage panels for thermal protection of the interior is tested in a solar simulator. Therefore, latent heat storage panels based on polymeric materials are specifically designed and mounted in the insulation of a solar thermal facade collector. The panel position and thickness (stacking) are optimized. The overheating protection efficiency of the optimized configuration is high: even at a harsh solar irradiation, the inner surface and interior air temperatures do not exceed comfort levels. The discharging and full regeneration of the latent heat storage during the night is evident. The results emphasize a high innovative capacity of polymeric latent heat storages and prove the overheating protection concept of preceding numerical simulations. (C) 2018 Elsevier B.V. All rights reserved.