Phase change material (PCM) in commercial buildings save energy by actively absorbing and releasing heat. PCMs help maintain comfortable building temperatures with the potential to reduce peak sensible cooling loads and annual energy consumption in climate zones with enough variation in day and night time temperatures.
Various materials have been considered for building applications, such as paraffin wax, biobased organic materials, and eutectic salts, to take advantage of the PCM latent heat capacities and high storage densities. Like conventional thermal mass, such as concrete or adobe, PCMs can store similar amounts of heat but with significantly less mass. PCMs maintain a near-constant temperature within the conditioned space while undergoing a phase change. Melting temperatures typically range from 70 to 80°F in building cooling applications. This temperature range is varied, based on application, to minimize the heating and cooling loads for the building while maintaining the comfort of its occupants. PCM research has been done for decades, but structural complications and flammability issues in prior PCM products have prevented adoption of the technology. Recently, some new commercial products mitigate these issues. Despite decades of research, the effect of PCM on energy consumption in buildings is not understood.