A Trombe wall that uses a phase change material (PCM) as the heat storage medium is usually called a PCM Trombe wall or PCM wall. A research project was conducted to investigate the performance of coupled novel triple glass (NTG) and PCM wall, which is simply called PCM wall in this paper, as a solar space heater. The south facade of a test room was constructed using PCM walls. Rubitherm (R) GR35 and GR41 were incorporated into the plaster of the walls as PCM. The ratio of the solar energy gain provided by the PCM walls to the heat load of the test room per month varied from 4% to 70%; daily overall efficiency of the PCM walls varied from 20% to 36%; and solar transmittance of the NTG varied from 0.45 to 0.55 during the heating period. The overall efficiency of the PCM wall including GR35 was higher than that of the PCM wall including GR41. (C) 2012 Elsevier Ltd. All rights reserved.