HVAC stands for Heating, Ventilation, and Air Conditioning. HVAC is a type of automation system which is used for handling air quality and thermal comfort given to the human environment for survival.

HVAC is based on thermodynamics, fluid mechanics, and heat transfer. Just like different types of automation systems, HVAC too is a type of automation system.

HVAC is one of the most important parts required when setting up a high-rise building, commercial complex, industrial unit, hospital, parking unit, hotels, etc. where air quality and thermal parameters need to be maintained so that the personnel around can live properly.

Traditional HVAC systems worked without PLCs; but nowadays, almost all of them have PLCs installed for better and more accurate control.

Types of HVAC Systems
The types of HVAC systems are classified as follows.

They are

• Split system
• Hybrid heat pump
• Ductless mini-split
• Ducted mini-split
• Packaged system

An HVAC System consists of the following components

• HVAC water chillers
• HVAC heaters
• Hot water generator or furnace
• Chilled water pumps
• Cooling water pumps
• Electrical power supply control or Motor control center (MCC)
• Cooling towers
  Piping for chilled water and cooling water or condenser side water
• Valves for chilled water and cooling water sides
• Air handling units (AHUs),
• Heating coils and cooling Coils
• Ducts in the ventilation system
• Fan Coil Unit and thermostats
• HVAC Diffusers and grills
• HVAC controls (instrumentation)
• HVAC software