Comfort Systems USA, Inc. is a provider of mechanical contracting services, which principally includes heating, ventilation and air conditioning (HVAC), plumbing, piping and controls, as well as off-site construction, electrical, monitoring and fire protection. It installs, maintains and repairs products and systems throughout its approximately 35 operating units in 81 cities and 89 locations throughout the United States. It operates primarily in the commercial, industrial and institutional HVAC markets and offers services for the industrial, healthcare, education, office, technology, retail and government facilities. It provides a range of construction, renovation, expansion, maintenance, repair and replacement services for mechanical and related systems in commercial, industrial and institutional properties. Its installation business related to newly constructed facilities involves the design, engineering, integration, installation and start-up of mechanical and related systems.