This standard specifies the test method for the phase change temperature regulation performance of building materials. It applies to the testing of the temperature regulation performance of building materials and their products. In this standard, terms and definitions include phase change temperature regulation performance, phase change temperature and latent heat of phase change. Phase change temperature regulation performance refers to the ability of a substance to regulate the temperature of a local space by means of phase change, characterized by phase change temperature and latent heat of phase change. Phase change temperature is the temperature at which a substance absorbs or releases heat from one phase to another at a specific temperature. Latent heat of phase change is the heat absorbed or released by a unit mass of a substance when it completely transitions from one phase to another under certain temperature conditions.