Phase-Change Blankets Conserve Energy in Pullen Hall

Tucked above the ceiling tiles in Pullen Hall is NC State’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 – either melting or freezing  – to help manage the temperature of the environment around it.

Phase-change blankets require no major changes to a building’s infrastructure, no maintenance and use no additional energy. This is a great option for older buildings like Pullen Hall, where it’s more difficult to upgrade the building’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.

“[The blankets] have definitely increased occupant comfort,” Potter said. “Before 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.”

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.