How Central Air Works And Why You Should Install It

12 June 2023
 Categories: , Blog


Central air conditioners chill air in a single location and then move the air throughout your home. Unlike window units or portable air conditioners, a central air conditioner can cool the entire home evenly and efficiently. It's essential to know how central air works when having one installed.

Central Air Basics 

An AC consists of an outdoor unit and an indoor unit. The system also uses a thermostat to control the temperature and a furnace or an air handler to circulate the air through ductwork.

The cooling begins when the thermostat detects that the indoor temperature exceeds the desired setting. It sends a signal to the outdoor unit to start the compressor, which pumps refrigerant through the system. The liquid refrigerant travels through an expansion valve that reduces pressure and temperature.

The evaporator coil allows the refrigerant to suck up heat from the indoor air and change to gas. The air handler blows cooled air through ducts and into the rooms of the house. The refrigerant cycle repeats until the indoor temperature reaches the thermostat setting.

Types of Central Air Conditioning Systems

There are two systems: split systems and packaged systems. A split system has separate outdoor and indoor units. In contrast, a packaged system has both units in one cabinet, usually outside or on the roof.

A split system is more common in residential settings, as it allows for more flexibility in installation and maintenance. A split system can also be combined with a furnace to heat the house. A split system typically consists of the following:

  • An outdoor unit with a compressor, a condenser coil, and a fan
  • An indoor unit with an evaporator coil
  • A thermostat 
  • Air ducts
  • A filter that cleans the air 

Packaged systems are more common in commercial settings or homes with limited indoor space. A packaged system can also provide heating and cooling but requires fewer components and less installation work. A packaged system typically consists of the following:

  • A single cabinet contains a compressor, a condenser coil, an evaporator coil, an air handler 
  • A thermostat 
  • A network of ducts that distributes the conditioned air 
  • A filter 

Regardless of your choice, a central air conditioning system has several benefits.


Central air offers many advantages over other types of cooling systems, such as:

  • Cooling your house with less energy than multiple window units or portable air conditioners
  • Maintaining a consistent temperature throughout your home, eliminating hot or cold spots
  • Producing less noise than other cooling systems, as most components are located outside or away from living areas

While central air can sometimes be more expensive than other units, such as window units, it's usually worth it.

Contact a local HVAC company, such as STA SO COOL HVAC, to learn more.