Phase Change Materials (PCM) oscillate between solid and liquid phase within a certain temperature range (Mansfield). When the environment’s temperature is higher than that of the PCM, heat transfers from the surroundings to the material, which creates a cooling effect and changes PCM’s state from solid to liquid. When the environment’s temperature is lower than that of the PCM, heat transfers from the PCM to the surroundings, generating a warming effect and PCM changes back to its solid state.
Researchers at the University of Nottingham Ningbo China ( UNNC) have developed a new PCM for room climate control that could be applied on wallpaper. This phase change material (PCM) retains and releases heat according to the specific temperature requirements for a building. The researchers claim large thermal energy storage capacity with fast thermal transfer properties than existing materials.
The news publication in "Building4Change" states that the material is said looks like a circular tablet. It can be manufactured in a variety of shapes and sizes, even in spray form as a microscopic film to surfaces.
The basic structure of the material can be engineered for a specific temperature before it is used. If, for example, the required optimum temperature in a room is 22°C, the material can be fixed so that it starts absorbing any excess heat above that temperature.
The material using a technique where phase change material of appropriate temperature are micro-encapsulated. The product is then used in a form to be applied as a coating on surfaces. The material adds thermal mass to the room and is designed to store thermal energy as latent heat. Latent heat is the thermal energy that is stored or released when a product changes state. The material within the microcapsules freeze at temperatures below it's phase change point and liquefy when the temperature rises. The product does not eliminate the need for insulation or air-conditioning but reduces the heat loss and reduces the load on air-conditioning during peak demand hours.
The university is said to already has a number of sponsors and partners involved in the research, including the Ningbo Science and Technology Bureau, which supported the initial two-year research, and private companies based in China.
UNNC is looking at further research to determine long-term environmental impacts of the use of the materials, determine ways to improve the production of the material to enhance cost efficiency and ensure the process is environmentally friendly, explore which types of paints can be used with the material.