Abstract: Apparatus for minimizing the transmission of long wave infrared energy without significantly affecting the transmission of solar energy to provide an energy efficient building component is disclosed. A flexible plastic substrate is used having a thickness of no more than approximately 20 mils. A long wave infrared radiation absorbing material is fixed to the plastic substrate. The substrate and the absorber in combination are at least 94% transmissive to visible solar radiation so that transmission of solar energy is substantially unaffected. However, the substrate and the absorber absorb sufficient long wave infrared radiation so that transmission of at least 80% of all incident long wave radiation is prevented, in large measure blocking the transmission of heat energy through the system.

Abstract: Apparatus for inhibiting the transmission of solar energy above a predetermined temperature range, but permitting transmission of said energy below that range, is disclosed. A layer of material is provided which undergoes a reversable, macroscopically non-mechanical change affecting the transmissivity of the material to solar energy in the desired temperature range. Because of such change, the material is at least 50% less transmissive to solar energy above the transition temperature range than below the range. This layer of material is mounted so that its physical configuration is substantially maintained.

Abstract: A building element which inhibits the change of the interior temperature of a building beyond prescribed limits approximating room temperature. A rigid porous matrix structure is provided in thermal communication with the building interior. A store of phase change material impregnates the matrix structure. The phase change material has a melting point within the temperature limits so that the material melts when the interior temperature of the building exceeds the temperature limits. Melting of the material absorbs heat and reduces the interior temperature of the building, until the material is entirely melted. Conversely, the material freezes when the interior temperature of the building falls below the temperature limits to release heat and increase the interior temperature until the stored material is entirely frozen. The store of phase change material is sealed within the matrix structure so that the material undergoes repeated changes in phase between liquid and solid.