Institute of Fundamental Technological Research

Different types of Phase Change Materials (PCMs) have been tested as dynamic components in buildings for at least 4 decades. Most of historical studies have found that PCMs enhance building energy performance. The PCMs store energy and alter the temperature gradient through the insulated cavity because they remain at a nearly constant temperature during the melting and solidifying stages. The use of organic PCMs to enhance the performance of thermal insulation in the building envelope was studied at the Oak Ridge National Laboratory during 2000 – 2009. PCMs reduce heat flow across an insulated region by absorbing and desorbing heat (charging and discharging) in response to ambient temperature cycles. The amount of heat that can be stored in PCMs is directly related to the heat of fusion of the material, which is between 116 J/g to 163 J/g (or 50 to 70 Btu/lb) for the most - popular micro encapsulated paraffinic PCMs, or fatty acid materials used in this research. This paper presents experimental and numerical results from the long-term thermal performance study focused on blown fiber glass insulation modified with a novel spray-applied micro encapsulated PCM. Experimental results are reported for both laboratory - scale and full - size building elements tested in the field. Test work was followed by detailed whole building Energy Plus simulations in order to generate energy performance data for different US climates.