There are three distinct types of muscles: skeletal muscles, cardiac or heart muscles, and smooth (non-striated) muscles.
HVAC technicians are responsible for the installation, maintenance and repair of heating, ventilation and air conditioning (HVAC) systems. As an HVAC technician, your job duties may include inspecting existing systems and making recommendations intended to improve the efficiency and/or safety of that system's performance. HVAC-R techs may also work on refrigeration systems.
Heating, air conditioning, and refrigeration mechanics and installers typically do the following: 1  Use blueprints or design specifications to install or repair HVACR systems. 2  Connect systems to fuel and water supply lines, air ducts, and other components. 3  Install electrical wiring and controls and test for their proper operation.