Project Based Learning In A First Year Chemical Engineering Course: Evaporative Cooling

The challenges of engaging first-year engineering students are well known. Many students come to an engineering curriculum poorly prepared and with substantial misunderstanding of what engineers actually do. Too frequently, recent high-school graduates are unprepared to make the commitment to do the hard work required to complete their degree in four years. Some students who might otherwise become successful engineers change their major to one that has more immediate appeal, is an easier pathway to graduation, or is taught by instructors who address the students' preferred learning styles directly. At engineering colleges around the country, many inventive programs have recently begun to address these issues. Along with recognition that the traditional lecture-based format is far from ideal, many programs and departments have created innovative problem-basedlearning first-year courses. The perception is that giving students the opportunity to design, build, and test a "widget" will engage them more fully, motivate them to study harder, make a more educated choice of major, and commit to the major. Students whose preferred learning style requires active, hands-on activity discover that engineering may suit them well, in contrast to what they may have concluded from lecture-based courses. This paper is a report on one such effort at the University of Nevada, Reno, funded by the Hewlett Foundation. A new course has been developed in chemical engineering with a greenengineering theme, and uses a project as a vehicle to learn teamwork, to practice engineering design, measurements, and graphical data representation. We also address academic study skills and use Felder's Index of Learning Styles (ILS) to enable students to be aware explicitly of their own learning style. The project is to design, build, and test an evaporative cooler, and is conducted in teams of 3 or 4 students, that endure for the semester. Assessment criteria include evaporative cooler performance, cost, safety, and style. Safety is given prominent focus repeatedly throughout the semester. Students learn how to use a psychrometric chart and apply it to rate the performance of their cooler. The nature of measurements is discussed. Teamwork skills, including problem solving, are addressed. Students practice engineering design in a formal manner, with several repetitions of design versus performance, safety audits, and cost playing important roles. The class incorporates several teaching methods, to target learners of all types. Sensors benefit directly from the project, and seeing the results of their work, while intuitive learners do well with the performance calculations, and also with the varied engineering calculations included in the text by Solen and Harb. Visual learners do well with the psychrometric chart and the design diagrams, while verbal learners gain from the classroom discussions and from the book reading. Active learners especially benefit from the incorporation of this project, since it requires hands-on building in a group. Reflective learners profit from writing the reports and completing the homework assignments. Both inductive and deductive learning styles are incorporated, since the nature of evaporative cooling is understood by all at some intuitive level, and we analyze the cooling by looking at rates of heat transfer, mass transfer, and thermodynamics. Finally, iterative design benefits both sequential learners and global learners. The project component of the class has been through two iterations, once in the summer of 2005, and again in the Fall of 2005. Preliminary results suggest strong student buy-in to the project. Disadvantages of the project include weather (geography), cost, and for some students, the discomfort of working with their hands for the first time.