To make the most of the educational and research opportunities provided by the Lewis Center, Oberlin partnered with the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) to install a comprehensive suite of sensors for monitoring environmental performance. Funded in part by a grant from the Andrew W. Mellon Foundation, 150 sensors that collect data on resource and energy flows were purchased and installed by students, faculty and staff.

The premise behind the AJLC's extensive data monitoring system is that real-time feedback on ecological performance increases awareness, connectedness, and motivation to act on the part of both building occupants and facilities managers. Our goal is therefore to make the flows of energy, cycling of matter and interactions between the built and natural environments visible and easy to interpret. This system also makes an ideal interactive learning tool for all who enter the Center and visit this website by revealing the flows of energy and cycling of materials through the AJLC building and landscape. New feedback of this type may be a necessary prerequisite for facilitating a more sustainable relationship between humans, technology, and the natural world.

This framework for visualizing resource consumption is currently being applied to student dormitories throughout the Oberlin campus. Visit the Campus Resource Monitoring System website to learn more.

Data Acquisition

Installation: Students, faculty and collaborators from the National Renewable Energy Lab installed over 150 environmental sensors in the AJLC building and landscape. Sensors that measure everything from energy consumption to CO2 levels to dissolved oxygen levels in wastewater were installed and wired to datalogging computers.

Sensors: The sensors utilized in the AJLC monitoring system translate environmental conditions and building performance variables into an electrical signal. There is a variety of different sensors deployed in the AJLC building and landscape. Below are some examples:

• Temperature - Temperature sensors utilized include thermistors and thermocouples. Thermistors are thermally sensitive resistors that exhibit a large, predictable and precise change in electrical resistance when subjected to a corresponding change in temperature. Thermocouples are sensors for measuring temperature. They consists of two dissimilar metals, joined together at one end. When the junction of the two metals is heated or cooled a voltage is produced that can be correlated with temperature.
• Electricity - Flows of energy in the AJLC (both production and consumption) are measured with pulse output WattNodes®. A pulse (electrical switch closure) is proportional to a fraction of a kilowatt-hour. Monitored electrical circuits include photovoltaic system output, total building consumption, lighting loads, heating, ventilating and air conditioning loads, and additional sub-systems within these categories.
• Water - Similar to electrical sensors, water flow meters in the AJLC produce a pulse (switch closure) for a fixed volume of water as it flows by (usually one gallon). Most water meters in the building also have totalizers that can be read manually.

Dataloggers: Raw readings from the various sensors are collected and processed by dataloggers before being sent to a PC server for analysis and display on the web. The three dataloggers used are made by Campbell Scientific, Inc., model name CR-10x. These are fairly standard devices in scientific research communities. The dataloggers upload data once every minute to the PC server via campus-wide ethernet.

Data Processing

Server Configuration: The PC server used is a 2.6-GHz P4 machine which collects and processes data.

Applications: This computer is responsible for collecting the data over the network from the dataloggers, putting it into a database, and performing additional functions on the data to calculate sensible values. The first version of the software for these tasks was written by Oberlin students Alex Maly ('02) and Eric Schwartz ('02). One important function of this software is calculating meaningful numbers for the website audience by aggregating sub-metered variables. For example, the total energy used for heating, ventilating and air conditioning (HVAC) systems is not measured with one sensor but rather with multiple sensors, so the PC server calculates this sum once every minute.

Data Display

Website: A newer version of this website premiered in late June 2004 with significantly improved graphics. The most recent revamping was released in the fall of 2005.

Atrium Display: The computer display in the AJLC's atrium was upgraded in January 2004 from a 19" flat panel LCD monitor to a 42" plasma display. New graphics were also installed on the plasma screen.

Please see the Credits page for more information.

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