Lennox International, Inc. engages in the design, manufacture, and marketing of products for heating, ventilation, air conditioning, and refrigeration. It operates through the following segments: Home Comfort Solutions, Building Climate Solutions, and Corporate and Other. The Home Comfort Solutions segment is involved in furnaces, air conditioners, heat pumps, packaged heating and cooling systems, indoor air quality equipment, comfort control products, replacement parts, and supplies. The Building Climate Solutions segment consists of unitary heating and air conditioning equipment, applied systems, controls, installation and service of commercial heating and cooling equipment, variable refrigerant flow commercial products, curb, curb adapters, drop box diffusers, HVAC recycling and salvage service, condensing units, unit coolers, fluid coolers, air cooled condensers, air handlers, process chillers, controls, and compressor racks. The Corporate and Other segment refers to the unitary heating and air conditioning equipment, chillers, air handlers, fan coils, fluid coolers, and compressor racks. The company was founded by Dave Lennox in 1895 and is headquartered in Richardson, TX.

Johnson Controls International Plc engages in the provision of building products, energy solutions, integrated infrastructure and next generation transportation systems. Its products and solutions include fire detection and suppression, security, HVAC equipment, building automation and controls, digital, industrial refrigeration, residential and smart home, retail, distributed energy storage, and batteries. The company was established in 1885 and is headquartered in Cork, Ireland.

Tecogen, Inc. engages in the production of commercial and industrial, natural-gas-fueled engine-driven, and combined heat and power (CHP) products. It operates through the Products, Services, and Energy Production segments. The Products segment designs, manufactures, and retails industrial and commercial cogeneration systems. The Services segment installs and maintains the cogeneration systems. The Energy Production segment sells energy in the form of electricity, heat, hot water, and cooling to customers under long-term sales agreements. The company was founded by George N. Hatsopoulos and John N. Hatsopoulos in 1987 and is headquartered in North Billerica, MA.