Field demonstration of an attic retrofit strategy using cellulose insulation and phase-change material

The U.S. Department of Defense (DOD) has set aggressive building energy performance goals to comply with the requirements of the 2007 Energy Independence and Security Act (EISA 2007), and is introducing state-of-the-art technologies into its new building design and building upgrade programs. A key part of this strategy is the identification, proof-testing, and introduction of promising new technologies into the building stock that will be needed to achieve mandated energy reduction goals. This article describes an attic retrofit strategy using batt and loose-fill cellulose insulation combined with phase-change material (PCM) applied in an existing DOD building. The subject building is located at Fort Bragg, North Carolina, and is a one-story building with ducts in the attic. Originally, the attic contained ceiling insulation and was unconditioned with soffit and gable vents. The project consists of three stages. First, the original attic was instrumented with temperature, heat flux and humidity sensors, and monitored over the heating and cooling seasons. In stage two, the attic vents were sealed and the roof decks, soffits, and gable ends were insulated with cellulose insulation. Finally, in stage three, low-cost bio-based PCM mats were installed on the interior surfaces of the cellulose insulation at roof decks and gables. Pre- and post-retrofit data are being collected over at least 9-month periods for each stage of analysis.