TECOGEN makes natural gas-fueled commercial and industrial cooling and cogeneration systems. Its products include chillers, water heaters, and other types of cooling, refrigeration, and cogeneration systems. Its product lines include TECOCHILL 25 to 400 ton engine-driven chillers, TecoFROST refrigeration, and TECOGEN cogeneration equipment. The company handles its own sales and marketing; it also provides nationwide service support. TECOGEN has installed more than 1,800 units throughout the US. The company was founded in the early 1960s and was spun off from Thermo Electron Corporation (a predecessor to Thermo Fisher Scientific) in 1987.