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.
HVAC Certification. HVAC, or Heating, Ventilation and Air Conditioning technicians are people specializing in the installation, maintenance and repair of our HVAC systems. They are required by the State Licensing Board (most of the state) and employers to obtain certification or licensure before they can practice as an HVAC technician.