This role requires in-depth knowledge of refrigeration, heating, and air conditioning systems — including chillers, cooling towers, Computer Room Air Conditioner (CRAC) units (DX and chilled water), rooftop units (RTUs) (DX and chilled water), and air handling units (AHUs). Job Duties and Responsibilities: The Journeyman HVAC Technician is responsible for the installation, repair, replacement, and testing of HVAC/R systems, control circuits, equipment, and appliances, as well as the maintenance of environmental control systems.