Phase-Change Blankets Conserve Energy in Pullen Hall

Tucked above the ceiling tiles in Pullen Hall is NC Stateā€™s latest energy-saving project. 

Last March, NC State Energy Management installed approximately 1,200 phase-change blankets in the ceilings of Pullen Hall. In just one year, the blankets have already contributed to a 5% reduction in chilled water consumption and a more than 10% reduction in steam consumption. 

According to Energy Project Manager Vincent Potter, phase-change blankets help stabilize indoor temperatures without using any energy from the building. If the temperature rises too high in a room, the blankets absorb excess heat, which is released when temperatures drop too low. While absorbing or releasing heat, the substances within the blanket go through a phase change ā€“ either melting or freezing  ā€“ to help manage the temperature of the environment around it.

Phase-change blankets require no major changes to a buildingā€™s infrastructure, no maintenance and use no additional energy. This is a great option for older buildings like Pullen Hall, where itā€™s more difficult to upgrade the buildingā€™s energy system to modern and more efficient technologies. 

The blankets are also manufactured using sustainable materials and renewable, plant-based byproducts. 

Energy Management works closely with the building occupants throughout this pilot project to ensure maximum building-occupancy comfort. Pullen Hall houses the Office of Global Engagement, Student Legal Services and University Housing.

ā€œ[The blankets] have definitely increased occupant comfort,ā€ Potter said. ā€œBefore the blankets were installed, occupants described varying temperatures from room-to-room in the building. After the blankets were installed, office temperatures have been much steadier.ā€

This project presents potential energy savings for other historic campus buildings. Energy Management will continue monitoring Pullen Hall until June before evaluating whether to use phase-change blankets in additional buildings.