An innovative roof coating using thermal energy storage materials from Arizona State University (ASU) spinout EnKoat could help reduce heat in several buildings at the school, including a section of the university’s largest preservation facility.
The company is collaborating with ASU and the Salt River Project (SRP), a nonprofit organization that provides water and power to residents in central Arizona.
According to ASU, while heat mitigation is a growing requirement for buildings and road surfaces in the desert Southwest, that control is especially critical for the facility’s high-density collections (HDCs). The HDC is described as a 40,000-square-foot (3,716.1 m2) repository for 2.5 million books, scholarly journals, and other historic materials stored at ASU’s Polytechnic campus. The contents of the building are kept at 50 °F (10 °C) and 30% humidity all year long.
The collaboration is for a two-year study, which uses sensors to track the temperatures and energy costs in two of three sections. One is featuring company’s proprietary coating system, IntelliKoat, and one without.
“SRP will compare internal building temperatures of the section coated with IntelliKoat to the section that has not been coated,” said Aashay Arora, EnKoat co-founder. “This will help them calculate energy efficiency improvement with (the) IntelliKoat system, especially at times when there is peak demand in the grid.”
Seamless, Monolithic Roofing Layer
Thermal energy storage (TES) materials can keep the heat out of vital spaces by transforming from solid to liquid and back again to store and release heat. For IntelliKoat, these TES materials are dispersed inside a coating, which is applied as a seamless, monolithic layer across the entire roof surface.
“Think of an ice pack in an ice chest,” Aguayo said. “The ice pack melts but can still keep the drinks at a certain temperature. Then, you take that ice pack and refreeze it again.”
“Now, envision that ice pack as a particle about half the diameter of a hair, and you can put that into any coating product — in this case, our IntelliKoat system,” Aguayo continued. “It’s not going to freeze at 32. It’s going to freeze and melt at the application-specific temperatures we design it for. In Arizona, we design it for a hot climate. In colder climates, we design it accordingly.”
“With IntelliKoat, as the temperature rises during the day, the particles change from solid to liquid. As it cools, they solidify again. In the coating, these TES materials are encapsulated, like the ice in the ice pack. They aren’t released into the environment and are able to maintain their performance for over 10,000 heating and cooling cycles.”
ActivTherm Encapsulation Process
EnKoat’s encapsulation process is known as ActivTherm. Moreover, the materials used in EnKoat products are made with bio-based renewable feedstocks and contain very little to no volatile organic compounds (VOCs), which means that they will not release toxic vapors upon application or over time.
EnKoat was founded while Aguayo and Arora were doctoral students in ASU’s School of Sustainable Engineering and the Built Environment (SSEBE).
“Originally, the team started looking for new ways to prevent thermal cracking in concretes,” said Narayanan Neithalath, the students’ advisor and a SSEBE professor. “When that was successful, we wondered if using the same technology could keep buildings cooler.”
Neithalath was able to secure research funding for the duo to “investigate if embedding TES materials into paint, plaster and stucco — three of the most common coatings for buildings — could maintain comfortable interior temperatures for houses and other structures.”
Their research was successful, and EnKoat was born.
Initial Focus on Flat, Low-Slope Roofs
While major corporations had already looked at using TES materials for building products, “it was a different application,” Neithalath explained. “They were using the technology to make gypsum board, not coating rooftops. Builders weren’t going to spend $70 instead of $12 per piece of gypsum board for drywall.”
When they were doctoral students, Aguayo and Arora initially installed the roof coating on the agribusiness center at the Polytechnic campus. Internal thermostats on both coated and uncoated portions of the building have been providing comparative monitoring for five years. While energy use was not tracked for that project, the results were impressive enough to bring SRP into the next phase of testing.
Currently, EnKoat is focused on coatings for flat and low-slope roofs, but they are investigating the development of a spray-on product for vertical surfaces. “This would be for a prefab wall inside a factory,” Arora said.
Future Goals and Partnerships
One recent application was for a chilled drinking fountain for the city of Phoenix. IntelliKoat was applied on one of two fountains as a test for future cooling fountain treatments. According to the city, the treatment did lower the temperature.
Arora and Aguayo have an ongoing research partnership and funding for which they are using ASU facilities. “They have grants from federal agencies, collaborations with industrial partners and a contract with a company that is manufacturing the coatings at scale,” Neithalath said.
Ultimately, the team hopes to create partnerships with manufacturers, distributors, contractors, and building owners throughout the country. According to ASU, being able to provide utility service providers and energy companies with a cost-effective and scalable solution to manage peak demands on the power grid is especially important given the increased demand from electric vehicles and artificial intelligence (AI) technologies.
“Our IntelliKoat system allows us to create next-generation solutions to decarbonize the built environment, not only here in the Southwest but globally,” Aguayo said.
“It also will potentially provide custom rebate solutions for SRP customers and serve as a tool to educate the industry as a whole… as to how these new technologies are able to both improve energy efficiency and reduce load demand on the power grid,” Matthew Aguayo added.
For more information, contact: EnKoat, (713) 424-9382, www.enkoat.com