This paper evaluates the discharging mechanism in a PCM (phase change material) to air heat exchanger for the purpose of space heating using a composite of copper foam and PCM. The composite system is modelled with both 2-D and 3-D computational fluid dynamics approach for different inlet air temperatures to consider the effect of room temperature using the thermal non-equilibrium model for the porous medium compared with the thermal equilibrium one. The results show the significant advantages of composite heat exchanger compared with a PCM only case. For the inlet air temperature of 22 degrees C, the composite unit is solidified in 43% shorter time with 73% higher heat retrieval rate compared with that for the PCM only. After 10 h, the temperature variation between the inlet and outlet of the air channels for latent heat storage heat exchanger system with the composite system is 41 degrees C and 34 degrees C for the inlet air temperatures of 0 degrees C and 22 degrees C, respectively, while it is 33 degrees C and 29 degrees C for the system with PCM only. This study show the possible usage of PCMs in the energy storage heaters by introducing metal foams which is not possible using PCM only alternatives. (C) 2019 Elsevier Ltd. All rights reserved.