Air Conditioning


Air Conditioning

Many homes in North America rely on split-system air conditioners, often referred to as “central air.” Air conditioning systems include a number of components and do more than just cool the air inside. They also can control humidity, air quality and airflow within your home. So before we answer the question of how do air conditioners work, it will be helpful to know what makes up a typical system.

What is cental air?

A typical air conditioning system, often referred to as “central air” or “split-system air conditioning”, normally includes the following:

  • a thermostat that controls system operation
  • an outdoor unit that houses a fan, condenser coil and compressor
  • an indoor unit (typically either a furnace or fan coil) that houses the evaporator coil and fan to circulate the cooled air
  • copper tubing that allows refrigerant to flow between the indoor and outdoor units
  • an expansion valve the regulates the amount of refrigerant going into the evaporator coil
  • ductwork that allows air to circulate from the indoor unit out to the various living spaces and back to the indoor unit

In its most basic description, the air conditioning process involves two actions that occur simultaneously, one inside the home and one outside the home.

  • Inside the home : (sometimes referred to as the “cold side” of the system), warm indoor air is cooled as it blows across a cold cooling coil full of refrigerant. Heat from indoor air is absorbed into the refrigerant as the refrigerant turns from liquid to gas. The cooled air is distributed back to the house.
  • Outside the home : (sometimes referred to as the “hot side” of the system), the refrigerant gas is compressed before entering a large coil in the outdoor unit. Heat is released outside as the refrigerant turns back to a liquid and a large fan pulls outdoor air through the outdoor coil rejecting the heat absorbed from the house.