ROOSEVELT UNIVERSITY CHOOSES TECOGEN CHILLER FOR OPTIMAL COOLING OF CHICAGO CAMPUS Tecogen's Natural Gas-Powered TECOCHILL Unit Selected For Lower Cost and Space Savings WALTHAM, Mass., December 3, 2001 - Tecogen, a leading manufacturer of commercial and industrial natural gas-powered air-conditioners, has been chosen by Roosevelt University to provide natural gas-powered cooling as part of an updated hybrid utility plant-a cost-effective power source that alternates between using electricity and natural gas for air-conditioning. Roosevelt's plant will begin operating in the spring of 2002 and will provide cooling to the university's Chicago campus, which consists of the Auditorium Building-a National Historic Landmark-and the Herman Crown Center Residence Hall. According to Roosevelt's energy consultants, the TECOCHILL® unit demonstrated several advantages such as a quick and easy installation and compatibility with the university's existing hybrid plant. "Roosevelt University needed an optimal cooling system that was flexible and cost effective," said John Nowakowski, senior mechanical engineer of Ketchmark & Associates, consulting engineers for Roosevelt University. "After conducting master plan studies for the campus and HVAC planning, the hybrid plant with a Tecogen chiller was the logical choice for this project. We recommended the Tecogen chiller because it demonstrated a greater cost and space savings and could meet the project schedule requirements." The hybrid plant will switch back and forth between Tecogen's natural gas chiller and an electric chiller, using whichever energy source is the least expensive at any time. This flexibility allows Roosevelt to avoid the high electric rates that have resulted from the pricing model imposed by deregulated electric utilities. Also, since the university's existing electrical service is unable to provide the 1,000 tons of electrical power that would be required for campus-wide cooling, a plant that could operate on less electricity was needed. The university decided to use a hybrid plant, which can produce the required cooling from a combination of both natural gas and electricity. The hybrid plant is composed of a new 400-ton Tecogen gas-powered chiller, a new 600-ton electric chiller and two existing 225-ton electric chillers. Tecogen's chillers allow commercial and industrial customers to significantly reduce their energy costs by running on natural gas, an abundant energy source that is efficient and environmentally friendly. The TECOCHILL systems have successfully met the most stringent air-quality standards in the United States. About Tecogen Tecogen Inc. operates in the distributed generation market and is a leading manufacturer of natural gas-fueled commercial and industrial cooling and cogeneration systems. Tecogen has an installed base of more than 1,000 units, which it supports through an established network of engineering, sales, and service support. Formerly a public subsidiary of Thermo Electron Corporation, the company is now privately held. Tecogen is based in Waltham, Massachusetts, with annual revenues of approximately $13 million.