Energy demands for cooling of the buildings will increase in the future due to expected climate changes and increased intensity of the urban islands. Thermo-active building systems show a high potential for reducing energy needs for cooling of the buildings. This article presents an experimental study of natural and mixed convection over thermally activated cooling wall. Mixed convection regime is generated by ventilation supply air jet flowing through longitudinal ceiling slot downward parallel to the cooled wall. Experimental results were used for developing of multiparametric models for local convective heat transfer coefficients for natural and mixed convection. Those models were afterwards used in TRNSYS simulation tool for modeling of the thermal response and energy consumption for cooling of typical office room with thermal activated cooled wall. Decrease in energy usage resulting from more intense convective heat transfer in case of mixed convection is presented. (C) 2013 Elsevier B.V. All rights reserved.