Heat Island Mitigation Strategy for Urban Areas Using Phase Change Materials (PCM)

Heat islands are urbanized areas that experience significantly higher day and night time temperatures than the surrounding rural areas on account of the influence of the buildings, roadways, and industries on the local weather. Heat island mitigation strategy depends on the weather patterns at the urban geographical location. Mitigation of heat island effect has been demonstrated by increased use of shade and materials that alter the reflectance and emissivity of the surfaces impacted by solar radiation. Interest in the use of PCM for urban infrastructure for further enhancing the mitigation through heat storage and liberation is more recent. Key physical properties needed for PCM use are the latent heat of fusion, thermal conductivity, density, and specific heat. This paper reviews the physics involved in choosing the right PCM for buildings, placement of PCM in the infrastructure, and modeling methods for optimal energy costs.