A team of university professors and students in Florida have caught the attention of the Environmental Protection Agency (EPA) for designing an air conditioning system that can run on solar power. Mechanical engineering students and faculty members at Embry-Riddle Aeronautical University
have won two grants from the EPA -- $15,000 last year and $89,996 this year -- to work on a 300W solar cooling prototype that captures the sun’s heat with a parabolic mirrored trough and a line-focus high-temperature concentrating collector.
The latest grant was awarded in April when the team won the EPA’s 10th annual People, Prosperity, and the Planet competition in Washington. The Embry-Riddle team’s project was one of seven selected from 35 competing teams by a panel of national experts convened by the American Association for the Advancement of Science during the 2014 National Sustainable Design Expo.
The current project is part of several years of work on solar thermal energy storage and solar cooling the Embry-Riddle researchers have done with the EPA’s support, Yan Tang, an assistant professor of mechanical engineering who’s working on the project, tells Design News.
She says the team has so far built a compressor refrigerator -- like ones used in mobile homes -- as an early proof-of-concept for the air conditioning system that is the project’s ultimate goal. “The refrigerator is different from the normal compressor refrigerators because it is driven by a heat source,” Tang tells us. “In our system, the heat source comes from the heat transfer fluid heated by the parabolic solar troughs. Our system design focused on the heat exchanger, which delivers the heat from the fluid to drive the absorption cycle.”
The next phase of the project, supported by the grant, will be to develop a one-ton solar-powered air-conditioning system that should be able to cover around 500 square feet, if it works as designed. One of the key objectives of the project is to evaluate the commercial benefits of such a system to see if there is a cost savings over traditional AC systems, she says.
While the system would have to be used in places where there is a lot of sunshine, key to its design is a thermal storage unit for storing energy that can be used at night or on rainy or overcast days, she says. Researchers will use the grant money primarily to purchase a one-ton lithium-bromide absorption chiller and a customized storage tank that will be included in the system.
Along with Tang, other Embry-Riddle faculty participating in the project are professors Sandra Boetcher, Marc Compere, and William Engblom. Student team members include Nicholas Wood, Kendra Atticks, Kirsten Kasper, Zach Judson, Gloria King, and Domenic Barsotti.