How Does an Air Conditioner Actually Work?

Your air conditioner is a modern marvel. It keeps your home or office cool, comfortable, and creates an indoor summertime oasis. If something goes wrong with your AC, it’s important that you understand how they work so that you can identify any problems before it’s too late! Today, we’re going to give you a crash course on air conditioner basics and what you can do to get the most out of yours.

Air Conditioner Background History

In 1902, Willis Carrier revolutionized the home and work environment with his invention of modern air conditioning. Initially created to improve workplace productivity in factories and commercial buildings, its benefits soon became evident for residential use.
Although the first air conditioners were bulky and expensive, they have become much more efficient and cost-effective over time due to their reduced footprint. Now, they come in various models that fit any space while meeting various needs at home or in office settings. And, by the way, Willis Carrier is deservedly in the Business Hall of Fame!

Types of Air Conditioner Units

The air conditioning market is more diverse than ever, with central AC systems, window-mounted units, and many other options.
However, before you decide which type of unit to buy for your home or workplace, weigh the pros and cons associated with each one.

Central Air Conditioners

The most popular type of air conditioner in residential homes, central AC units are usually installed in attics or on roofs. They comprise an outdoor unit containing the compressor and condenser and an indoor air handler circling cool air throughout the home via ducts.

Cassette Air Conditioners

Cassette air conditioners are most commonly used in commercial buildings, although they can also be found in some residential homes. They are installed directly into the ceiling and feature an internal fan that circulates cool air through a small grille designed to blend into the décor of your home or office.

Ductless Mini-Split Air Conditioners

Ductless mini-split air conditioners are ideal for smaller spaces and those hard-to-cool areas of the home. These consist of an outdoor unit connected to one or more indoor units through a set of copper pipes, allowing you to cool specific rooms as needed. Compared to traditional ducted vents, indoor units in mini-split systems have thinner tubes and cable connections that enable them to be installed in more places.

Commercial Air Conditioners

Commercial air conditioners are larger and more powerful than residential units. They’re designed to cool large industrial spaces, such as warehouses and factories, that often require higher cooling power. These systems usually feature multiple compressors and evaporator coils that can provide comfortable cooling for up to 200,000 square feet of space!

Window Air Conditioners

Window air conditioners are the oldest and simplest type available. They sit in a window or wall opening, cooling a single room. Window units are usually affordable and easy to install, making them great for small apartments or spaces that don’t require powerful cooling.

Split Air Conditioners

Split air conditioners comprise two separate components, the indoor unit, and the outdoor unit. The indoor unit is mounted on an interior wall and distributes cool air throughout the room using a fan, while the outdoor unit houses the compressor and condenser. Split units are usually more powerful than window units and provide more consistent cooling.

Air Conditioner Parts

While air conditioners may seem like highly complex machines, they are actually made up of a few simple components. Understanding the parts and how they work together can help you make better purchasing decisions when shopping for air conditioning units or replacing parts.

Evaporator Coil

The evaporator coil is an essential part of any air conditioning system. This copper tube, also known as the “indoor coil,” absorbs heat inside your home and passes it outside. The coil is filled with refrigerant gas, which helps to cool it down by drawing in warm air from your home.


The compressor is the engine of your air conditioning system, acting like a powerful pump to spread refrigerant gas through coils that absorb heat from inside and cool down your home. It works continuously to provide reliable cooling all summer long.

Condenser Coil

Tucked away in its outdoor unit, the condenser coil is a copper tube that shields heat by releasing it from refrigerant gas and cooling it down before entering the evaporator coil.

Expansion Valve

Your expansion valve is your home’s temperature regulator that keeps an eye on pressure levels. It calibrates the refrigerant gas flow to your evaporator coil accordingly, providing just the right amount of cool air conditioning or cozy warmth.

Air Conditioning Cooling Cycle Steps

The cooling cycle is the process that takes place when your air conditioner is running. It starts as soon as you turn on the unit and continues until it reaches the desired temperature set on the thermostat. Here is a simple step-by-step breakdown of what happens during an air conditioning cooling cycle:
  • The hot air inside your home is drawn into the evaporator coil.
  • Refrigerant gas in the coil absorbs the heat and cools it down.
  • Cooled air is then circulated back into your home through a fan.
  • Hot refrigerant gas flows to the condenser coil outside, cooled down by external air.
  • The cooled refrigerant gas is then returned to the evaporator coil, and the cycle begins again.
  • Once the desired temperature is reached, the air conditioning unit will automatically shut off until it is needed again.

AC Efficiency Tips: Stay Even Cooler

Hot summers require a cool house! However, the hotter it gets, the more expensive your AC is to run. To get the most out of your air conditioning unit and reduce energy costs, we’ve put together few simple tips you can follow:
  1. Set your thermostat one or two degrees higher than usual when leaving the house for an extended period.
  2. Keep your air filter clean to ensure optimal operation and efficiency.
  3. Check the coils on the indoor and outdoor units regularly to ensure they are not clogged with dirt or debris.
  4. Seal any cracks or gaps around windows or doors where cold air may be escaping.
  5. Use a timer to ensure the air conditioning unit only runs when necessary.
  6. Keep curtains and blinds closed during the day to reduce heat gain from sunlight.
  7. Use ceiling fans or portable fans in addition to your air conditioner for extra cooling power.

Air Conditioning Maintenance

Regular air conditioning unit maintenance is essential for optimal performance and efficiency. It’s a good idea to have an HVAC technician like Moore Home Services come out once or twice a year to check that everything is in order and replace worn-out parts. Potential issues such as clogged or leaking lines, damaged components, and inadequate airflow will be assessed during the inspection and dealt with before they become significant issues.

Sweating? Don’t Sweat It! Call Moore Home Services

Don’t sweat out the summer! Call your friends at Moore Home Services to schedule your AC maintenance today and stay cool as the weather heats up.