A general problem of most solar thermal systems is the need for thermal storage in order to balance supply and demand of heat over a certain period of time. A possibility to employ latent heat of fusion in phase change materials (PCMs) for thermal energy storage in air-based solar thermal systems was investigated using laboratory experiments and numerical simulations. A heat storage unit containing 100 aluminium panels filled with a paraffin-based PCM was used in the investigations. The experiments were carried out in a lab environment with an electric air heater as a heat source. A numerical model of the unit was developed and implemented as a type in the TRNSYS 17 simulation tool. The results of the simulations with the developed model show a good agreement with experimental results. Subsequently, the model was used for a parametric study analysing the influence of certain parameters. The performed investigations showed a potential of the use of latent heat thermal storage in air-based thermal systems with a narrow temperature operation range. (C) 2013 Elsevier B.V. All rights reserved.