Experimental study of PCM effects on indoor temperature in lightweight buildings

Phase change materials (PCMs) integrated into lightweight building envelopes were experimentally evaluated to assess their impact on indoor thermal performance. A PCM test house and a reference test house were examined under two conditions: without ventilation and with night ventilation. The experiments were conducted under the climatic conditions of the Republic of Serbia, in Belgrade, at the Vinca Institute of Nuclear Sciences. Two observation periods were defined to evaluate the thermal behaviour of the test houses, with four thermal cycles monitored in each period. Results indicate that, on hot sunny days, the PCM test house achieved maximal indoor air temperature reduction of 3.5-4.8 ?C during the non-ventilated period and 4.2-5.9 ?C during the night-ventilated period, while reducing thermal load levelling (TLL) by 64.1-72.5% and 45.5-49.5%, respectively. The average indoor temperature reduction (AITR) ranged from 0.03-6.12% in the first period and from 3.19-6.54% in the second, confirming the potential of passive PCM application for improving indoor thermal stability. These findings show the practical benefits of PCMs in enhancing energy efficiency and indoor thermal comfort in lightweight buildings.