Evaluating A Remotely Accessed Energy Laboratory

Web-based monitoring and control of instructional laboratory equipment has become common. It is less clear how well remotely accessed laboratories satisfy the learning objectives for engineering technology courses. This paper describes a web-enabled energy laboratory featuring both solar energy and HVAC systems. Although the facility is physically located on the West Lafayette campus of Purdue University, the equipment is used by students in Mechanical Engineering Technology programs located across the state of Indiana. The discussion also evaluates the performance of students who access the laboratory over the Internet, without actually seeing the equipment in person. The viability of remotely accessible laboratories has become an important issue as engineering and engineering technology programs struggle to deliver lab-based distance education courses. Rationale for Web-Based Energy Labs What happens when the demand for energy exceeds the supply? This is a realistic (and scary) question that highlights the need for emphasizing sustainable design in undergraduate engineering technology programs. The Energy Information Administration predicts that in just two decades the U.S. will need 175 quads (1 quad = 10 15 Btu’s) to meet annual energy demands. 1 That is 75% more energy than is used today and runs counter to expectations for future energy availability from traditional sources. It is important to recognize that the energy challenge extends beyond the need for new sources. “Sustainability” is a popular term that takes a comprehensive view of energy. In addition to energy efficiency, sustainability incorporates renewable sources, life cycle costs, and environmental impacts into energy decision making. The resolution of complex issues like global warming or an over-reliance on foreign oil requires a broad sustainable view of energy resources. Commercial buildings are one obvious point of emphasis for sustainable design. The energy for heating and cooling commercial buildings accounts for at least 40% of the annual U.S. energy consumption. Despite some improvements over the past 30 years, many commercial buildings continue to waste energy. The Environmental Protection Agency estimates that U.S. businesses forego at least 20 billion dollars in operating costs each year due to inefficiencies in their buildings. 2 P ge 10591.1 Proceedings of the 2005 American Society for Engineering Education Annual Conference & Exposition Copyright © 2005, American Society for Engineering Education Engineering technology programs are ideally suited to teach sustainable design as it applies to commercial buildings. The laboratory-based coursework makes students familiar with the size, sophistication, and opportunities to improve the performance of real world equipment. Unfortunately, it is always difficult to provide enough state-of-the-art equipment to engage and teach large numbers of students. A well-equipped energy laboratory might feature one comprehensive air handling unit or one solar energy installation, but it is not possible for large numbers of students to have direct access to this equipment in the context of a brief two-hour laboratory period. The challenge of operating and maintaining modern laboratory equipment is particularly acute for large engineering technology programs that operate from more than one location. The Department of Mechanical Engineering Technology (MET) at Purdue University offers an Associate’s Degree at seven different locations in Indiana. Rather than functioning autonomously, the seven sites cooperate to provide a high quality technology education that is readily accessible to anyone in the state. Detailed learning objectives for all MET courses are published to help insure consistency between geographically separate locations. Despite the close collaboration, there is a large amount of variation between the laboratory facilities at the different sites. The MET program at the main West Lafayette has the largest enrollment, which justifies more extensive laboratory facilities and technician support. The six smaller MET programs at the other statewide locations do not have the resources to duplicate all the experimental equipment. As an example, consider a typical adult student pursuing an MET Associates degree at the Purdue statewide location in New Albany, IN. Career and family obligations limit his/her coursework to two evening courses each semester. The experimental work at New Albany is limited because the energy lab, hydraulics lab, and controls lab occupy the same space. It would strengthen the overall Purdue MET program if sophisticated laboratory equipment were supplied in a format that meets the constraints of this non-traditional student. In a stroke of good fortune, the key technology for improving energy efficiency in commercial buildings is also supplying a ready-made solution to the challenge of providing modern laboratory equipment to large numbers of undergraduate students. The Environmental Protection Agency estimates that a typical business can reduce its overall energy costs up to 30% by implementing a comprehensive energy strategy that includes computer controlled lighting, ventilation, and air conditioning equipment. 2 Building Automation Systems (BAS) monitor hundreds of data points (temperature, pressure, air flow, occupancy, power, etc.) to maintain comfortable and healthy indoor conditions while minimizing operating costs. Like most modern business enterprises, BAS have rapidly migrated toward network technologies that provide universal access to data via the Internet, cell phones, and web-enabled PDA’s. This rapid transformation is a bonanza for educators. Large amounts of energy data, from all types of equipment, can be readily accessed over the Internet. Instead of a traditional laboratory, where students share measurements while working in large groups, individual students directly access a wide variety of data from a networked personal computer. The webbased platform also offers exciting opportunities for asynchronous distance learning. P ge 10591.2 Proceedings of the 2005 American Society for Engineering Education Annual Conference & Exposition Copyright © 2005, American Society for Engineering Education Web-Based Data Collection for Energy Lab Figure 1 shows two small HVAC systems in the Applied Energy Laboratory at Purdue University. The equipment to the left is a laboratory-scale forced air system, which mimics the air handling systems found in small commercial buildings. The equipment to the right is a laboratory scale hydronic system, which is used for heating and cooling larger commercial buildings. Figure 1 clearly shows that neither system is particularly attractive for teaching. Most of the interesting heat transfer components and instrumentation are covered by insulating panels. Figure 1. Direct access to HVAC equipment provides little insight to equipment performance. Following trends in the HVAC industry, a web-based building automation system was created for monitoring and controlling the forced air and hydronic equipment. Each system has a local controller with an IP address that transmits data over Ethernet to a network server. The network server uses WebCtrl software from Automated Logic Corporation to acquire and post real time performance data in an html format. This open protocol allows any computer user with Internet access and a web browser to view live energy data. WebCtrl features password protection to limit access by unauthorized users. Rather that making direct measurements with the HVAC equipment, Figure 2 shows that a web-based graphic interface gives students a much more complete view of equipment performance. The three dimensional schematic presents a logical overview of all the equipment on the forced air system. It also shows real time temperature, pressure, flow, and power consumption at appropriate locations. In addition to the instantaneous data, building automation systems also store trend data. Instead of viewing a temperature snapshot, it is usually more helpful to look at how temperature varies over the course of a day. The HVAC equipment is only one component of the remotely accessible energy lab. In previous years, solar heating and photovoltaic equipment has been connected to the web ,3,4 . The remotely accessed energy laboratory has now reached a critical mass, where a variety of sustainable design concepts can be introduced in several different courses. P ge 10591.3 Proceedings of the 2005 American Society for Engineering Education Annual Conference & Exposition Copyright © 2005, American Society for Engineering Education Figure 2. A web-based graphic interface clearly shows HVAC components and performance. Overview of Remote Access Laboratory Environment Web-based instructional laboratories are not a new concept. An on-line controls lab at the University of Tennessee at Chattanooga has been operational for nearly 10 years. 5 Other well-known web-based laboratories feature experiments on dynamic systems 6 , mechatronics 7 , and lasers 8 . Despite the diverse technical content, one unifying theme is funding. To offset the relatively high startup costs, many web-based instructional laboratories have been developed with financial support from the National Science Foundation. Other web enabled laboratory projects are more ambitious. Bismarck State College has a web-based laboratory that is one part of an on-line associates program in Power Plant Technology 9 . The concept for the “Cyberlab” is even more intriguing. Cyberlab is an Internet hub that universities and private enterprise use to offer remote laboratory experiments for a fee 10 . These web developments suggest that distance education for laboratory-based degree programs is quickly becoming a reality. Table 1 is a brief summary of the web implementation for the remotely accessible energy laboratory at Purdue. It emphasizes that the laboratory encompasses more tha