Energy Performance Analysis of Building Envelopes Utilizing Blown Fiber Insulation with Microencapsulated Phase Change Material (PCM)

Phase change materials (PCMs) are an emerging technology with the potential to dramatically reduce cooling energy consumption and peak cooling demand in buildings when applied properly. Despite reported international progress in this area, a lack of clear application strategies for PCM applications (e.g., phase transition temperatures, enthalpy profiles, material configurations, HVAC schedules, etc.) remains a major barrier to greater use of PCM products in buildings in the U.S. PCM–insulation mixtures function as lightweight thermal mass components. It is expected that these types of dynamic insulation systems will con-tribute to the objective of reducing energy use in buildings. In this paper, dynamic thermal properties of a material in which phase change occurs are analyzed, using a temperature-dependent specific heat model. Integrals for the total heat flow in a finite time interval, across the surface of a slab of the phase change material have been derived. Simulations have been performed to analyze heat transfer through a light-weight building envelope assembly with PCM enhanced insulation for a variety of external climate thermal conditions. Results of the simulations indicate that for the cyclic processes, the effect of PCM in an insulation layer, results in notable time shifting of the peak-hour heat fluxes and in reduction of the total heat flow, resulting in re-duced cooling loads