Arhitektura i Urbanizam (Jan 2009)
Analyse of possibilities of increasing housing energy efficiency by application of phase-changing materials
Abstract
Refurbishment of existing building stock using energy-saving phase-changing smart materials and technologies, in addition to improved indoor climatic conditions, offer an opportunity for increasing housing energy efficiency and value. This fast developing technology becomes increasingly cost-effective with much shorter payback periods. However, it is undertaken only on a limited scale; because of lack of knowledge about their changeable properties and dynamism in that they behave in response to energy fields. Main characteristics, which make them different form others, are: immediacy transience, self-actuation, selectivity and directness. Phase change processes invariably involve the absorbing, storing or releasing of large amounts of energy in the form of latent heat. These processes are reversible and phase-changing materials can undergo an unlimited number of cycles without degradation. Since phase-changing materials can be designed to absorb or release energy at predictable temperatures, they have naturally been explored for use in architecture as a way of helping deal with the thermal environment in a building. Technologies based on sealing phase-changing materials into small pellets have achieved widespread use in connection with radiant floor heating systems, phase change wallboards, mortar or facade systems. Thermal characteristics of existing buildings can be improved on increasing their thermal-stored mass by implementation products of phase-changing smart materials. In addition to contributing to carbon reduction and energy security, using phase-changing materials in the building sector stimulates innovations.
