Tecogen Inc. is a company that designs, manufactures, markets, and maintains industrial and commercial cogeneration systems, offering a variety of products and services, including air-conditioning and refrigeration chillers, gas engine-driven refrigeration compressors, and water heaters. The company also provides long-term maintenance contracts, parts sales, and turnkey installation services through a network of field service centers in the US and Canada, and installs, owns, operates, and maintains distributed generation systems. Tecogen serves a wide range of clients, including hospitals, hotels, factories, and indoor growing facilities, among others, and was incorporated in 2000 in Massachusetts.