Building Energy Technology: PCM Enhanced Building Envelopes

Fraunhofer Center for Sustainable Energy Systems

Scanning electron microscope (SEM) images of microencapsulated PCM mixed with cellulose fiber insulation, blown fiberglass matrix and fiberglass, and polyurethane foam.

Project Motivation

Traditionally, the thermal design of building envelope assemblies is based on steady-state energy flows. In practice, however, building envelopes are subject to varying environmental conditions. Design work to support the development of very low-energy homes shows that conventional insulation may not always be the most cost-effective energy solution.

 

This project focused on analyzing building envelopes that had been enhanced with phase change materials (PCMs), which can simultaneously reduce total cooling loads and shift peak-hour loads.

 

Finding Cost-Effective Insulation Options

Fraunhofer CSE's Building Enclosures team performed an economic analysis to evaluate the cost effectiveness of simple PCM-enhanced building envelopes and find cost levels at which PCMs can be cost competitive with conventional thermal insulation.

 

The study team selected two basic PCM applications for analysis: dispersed PCM applications and simple building board products using concentrated PCMs. The  team then used these results as performance benchmarks for different PCM configurations that were tested in the United States for different building applications. This work did not, however, attempt to optimize PCM configurations. 

 

Finally, the study team analyzed several potential methods for future cost reductions for PCM-enhanced building applications.

 

A Building America Project

This assessment work was one of several research projects undertaken by a Fraunhofer CSE-led research team under a task order from the US Department of Energy's Building America Program.