Experimental investigation and modelling of a low temperature PCM thermal energy exchange and storage system

•We present an experimental pilot of latent heat thermal energy storage device.•We propose a 1D model of the storage device transferring heat into air during the discharge phase.•We compare experimental measurements and numerical simulations to validate the model.•We propose a differential model of a building and connect it with a model of LHTES device.•The capability of the LHTES model to contribute to design a process (sizing) is qualified.