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. As of December 31, 2016, the Company installed, maintained, repaired and replaced products and systems throughout its 35 operating units in 84 cities and 91 locations throughout the United States. The Company operates primarily in the commercial, industrial and institutional HVAC markets and offers services in the industrial, healthcare, education, office, technology, retail and government facilities. The Company provides a range of construction, renovation, expansion, maintenance, repair and replacement services for mechanical and related systems in commercial, industrial and institutional properties. The Company also provides remote monitoring of temperature, pressure, humidity and air flow for HVAC systems.