How Does Central Air Conditioning Work?

It’s a hot summer night, and your A/C unit has yet again made it nice and cool for you to enjoy your sleep. But have you ever wondered how does it actually work, this giant refrigerator-like device that just blows lovely, cool air at the temperature you need, when you need it?

Here’s what air conditioning is and how it works:


Your central air conditioner cools your house by cycling refrigerants (liquid agents) through the central heating and cooling system, and delivering chilled air through ductwork. It actually does use the same types of components, materials, and systems as a refrigerator.

Every A/C consists of three main parts – a condenser, an evaporator, and a compressor.

Refrigerant circulates through copper tubing (that runs between the evaporator and the condenser), receives and releases heat as it raises and lowers in temperature, changing from liquid to gas and then back to liquid; it’s especially cold when it begins to circulate through the indoor coil.

As a vapor, refrigerant travels to the outdoor compressor, which pressurizes it and moves it through the outdoor coil, where it dissipates the heat through coils or thin metal “fins”. The refrigerant then passes through an expansion device that converts it to a low-pressure, low-temperature liquid, which returns to the indoor coil.

An air handler or furnace cabinet is equipped with a blower that pushes the chilled air throughout your house. This appliance, typically located in an out-of-the-way place such as a basement or attic, pumps chilled air throughout the house through a system of air ducts.

As indoor temperatures rise and fall, one or more thermostats in the house will control the turning off and on of the cooling system. When the thermostat signals the A/C to lower air temperature, a whole cycle begins again.

It starts with the air-handling unit kicking on, pulling room air from various parts of the house through return-air ducts. Filters play an important part, as air is drawn in through them, removing airborne particles, such as dust and lint, and even microscopic pollutants in case of sophisticated filters. The air is then routed to air-supply ductwork through which the blower pushes it back to the rooms.

An AC unit also helps dehumidify your home – a big plus on the east coast during the scorching heat. It can also decrease wear and tear on your system from less starting and stopping.

The efficiency of the air conditioner can be a very important feature, especially since during hot summer months, when your A/C runs a lot, it can consume a lot of energy.

Call a professional to schedule air condition maintenance visit, which can include cleaning the inside and outside units and other maintenance tasks that will increase the efficiency of your system. If you need a new A/C unit, it’s important to choose one that is designed for energy efficiency and sized properly for your house.

Rely on UGI Heating, Cooling & Plumbing air condition company and our skilled HVAC contractors to help you with your AC service or air condition repair.

Make an appointment today with the leading HVAC company for all of your air condition repairs and installations in Lehigh Valley, PA, Harrisburg PA, Lancaster PA, Reading, PA that are right for your home needs, budget, and environment: 1-833-980-3496.