Team Members:
Bernadette Magalindan – Ph.D. student in Mechanical Engineering at the University of Texas at Dallas
Kiyan Bhalla – Master’s student in Management Science at the University of Texas at Dallas
Zainab Faheem – Master’s student in Mechanical Engineering at the University of Texas at Dallas
Zhihao Ma – Ph.D. student in Civil Engineering at the University of Utah
Advisor: Dr. Shuang Cui
School: The University of Texas at Dallas & University of Utah
Challenge: Taking Comfort to the Extreme
The objective of this challenge is to improve occupant indoor thermal comfort in buildings in the United States located in extreme climates or locations prone to extreme weather events by focusing on the environmental factors that determine individual satisfaction within indoor atmospheres.
Project Title: Climate-Resilient Overclad Roofing: A Synergistic Radiative Cooling and Thermal Energy Storage Approach to Combatting Effects of Rising Global Temperatures
Solution: Passive thermoregulation of buildings presents a sustainable means to alleviate the ever-growing and carbon-intensive demand for thermal comfort. Although emerging radiative cooling (RC) technologies effectively enable one-way heat rejection and achieve cooling, they alone cannot fully satisfy all needs for thermal comfort – namely, the need for warmth in cold weather. In this work, we developed a dual-functional material, composed of microencapsulated phase change materials (mPCM) embedded in delignified wood pulp cellulose fibers (CFs), for energy-efficient thermal management of buildings through RC and thermal energy storage (TES). In warm weather, RC assists the re-crystallization of mPCM; in cold weather, TES serves as a valuable complement to RC by offering passive heating to offset excessive cooling. The dual-functional material exhibits 95% of solar reflection that ascribes the scattering by the CFs and mPCM, whereas the intrinsic emissivity of cellulose produces a strong RC effect. Meanwhile, TES through mPCM achieves a latent heat of 156 J/g with excellent shape stability. This material solves the typical shortcomings of RC and TES through their synergetic performance, demonstrated by outdoor testing and computational modeling. Whole-building simulations show this innovative approach can reduce thermoregulation-associated energy use by 7.2% in hot and dry climates (Phoenix, Arizona). Additionally, fabricating the material from abundant wood waste and cellulose promotes carbon sequestration and offers a promising avenue for the development of sustainable building materials for energy-efficient thermal regulation.