Entech keeps Texans cool and safe. The company, which was founded in 1981, has business units that provide air-conditioning, heating, and refrigeration equipment and services in about a half-dozen cities across the Lone Star State. Entech also offers integrated-system building automation that syncs HVAC controls, access controls, security, closed-circuit television, alarms, and other automated systems. The company keeps its systems running by offering design, installation, maintenance, and repair of HVAC and refrigeration. Other products and services include rebuilt cooling towers and HVAC and power equipment rentals.