If you are new to the world of indoor cooling, you may wonder what is a central AC system. Some of the best air conditioners, after all, are central designs that provide whole-home cooling. So what is an ac unit in the first place, what is a central air conditioning system in contrast to other options, what are the benefits of using one in your space, and should you purchase one for your home? Central air is a cooling system that cools the whole house. It has a big unit outside that cools the air and sends it through ducts to every room. It keeps the temperature comfortable and works better than individual air conditioners.


  • Central air conditioning systems cool off the whole house at once, and not just a single room like window AC units. Some also feature heat pumps for heating.
  • Modern central AC systems integrate with smartphones and other smart devices with robust thermostat controls.
  • Maintaining a central air conditioner is fairly simple, just hire a pro technician for an annual inspection and replace the air filter as needed.

What is a Central Air Conditioner?

Before you can learn what is wrong with your central air conditioner, you need to know what it is and how it works. Unlike window units and portable air conditioners, central air cools the entire home at once, not just a single room. This is something all central units share, even if they offer different temperature ranges, causing some to ask what is the coldest temperature for an air conditioner. However, there are other whole home AC you can check out, too, like our comparison of mini split vs central air.

Insider Tip

Be sure to clear away large items of debris from the outdoor unit every once in a while, as they can impede functionality.

Benefits of Using a Central AC

Central air conditioners work via an outdoor unit exposed to your local climate that features a condenser and compressor that cools outdoor temperatures and sends the outside air through ducts and vents to an indoor unit in the home. This design allows for many benefits of using a central AC.

For example, installing a smart thermostat and using it in the summer allows you to set temperature preferences that will turn your air conditioning system on and off throughout the day, conserving energy and potentially lowering your utility bills. Additionally, by investing in regular maintenance of air ducts, you can reduce energy costs.

Ease of Use

Though tougher and pricier to install than a window air conditioner or a portable air conditioner, central units are extremely easy to use. They’re also more efficient because they evenly cool an entire apartment or home, ensuring a consistent temperature throughout the summer months. This is thanks to modern thermostats that integrate with smartphones and smart assistants, allowing you to alter cooling schedules on the fly. As a matter of fact, when central air systems are running smoothly, you will never have to interact with any component other than the thermostat controls.

Raising or lowering the indoor temperature of your entire house is as simple as turning a dial, and you can rest assured that the operating costs will be lower.

Modern Features

Central AC units have a long way since the halcyon days of the 1960s and 1970s. Modern units boast all kinds of modern features that go way beyond smart device integration. For instance, many new central air conditioning systems boast multi-zone cooling. What does this mean? It means you can set different temperatures for different rooms. This helps save on energy bills, as you can simply turn off the AC to rooms that are barely used. Some newer models also eschew ducts entirely.

STAT: In a split-system central air conditioner, an outdoor cabinet contains the outdoor heat exchanger, fan, and compressor, and an indoor cabinet contains the indoor heat exchanger and blower. (source)

Easy Maintenance

Maintaining your central unit is fairly easy, just hire a pro for an annual inspection and keep on top of the air filters. In general, you should clean or replace your air filters every two to three months. You should also know how to clean a central air unit to keep it running optimally.


How does an air conditioner work?

An air conditioning unit works to reduce humidity levels and cool the room by a certain number of thermal units via condensers, compressors, ducts, and vents.

What is included in a central air conditioning system?

A typical central air conditioning unit includes many features, but central systems differ in some regards. Some are ductless, while others include heating elements.

Which should you choose?

It depends on your budget, as the average cost of a central unit is more than a window unit. Choose based on preference, if you want heat pumps, go with that type of unit. You should also look into SEER, also called the Seasonal Energy Efficiency Ratio.

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