Updated at: 05-10-2022 - By: Sienna Lewis

It’s not uncommon for your house to become unbearably hot during the summer. A window air conditioner is something you’ve probably seen before. However, are you familiar with what they are and how they work from a young age? Window air conditioners cool the room by evaporating warm air and moisture from the room.

Central air conditioning systems are more expensive than portable air conditioners, making them popular in many homes. Keep reading if you’d like to learn more about how they function and the advantages of having one installed in your house! A window air conditioner is the best way to keep your home cool during the sweltering summer months.

History of Window Air Conditioners

Many groundbreaking discoveries were made in the field of air conditioning during the nineteenth century. A doctor by the name of Dr. John Gorrie is credited with inventing one of the most noteworthy innovations. In 1840, Dr. Gorrie invented an ice-making machine in order to treat patients suffering from malaria’s high fevers.

Such inventions were scorned at the time. For many people, devising a device that could essentially ‘alter’ the weather was an act of sin. People thought that doing so was blasphemous and interfering with Mother Nature.

HVAC Systems Review - How Does A Window Air Conditioner Work? - YouTube

The first air conditioner was invented in 1902 by Willis Haviland Carrier, the inventor of modern air conditioning. For the Brooklyn printing firm Sackett-Wilhelms Lithographing and Publishing Company, he designed an air conditioner. High temperatures in the printing plant caused the paper to wrinkle and the ink to be misaligned, necessitating the installation of air conditioning.

People took a while to get used to air conditioners since they were so large and cumbersome back then. It didn’t help that they were also prohibitively expensive. Smaller, more domestic air conditioners first appeared in the early 1930s.

Engineer Henry Galson developed a more cost-effective and space-saving window air conditioner later on.

An air conditioner that could be placed on the window ledge was devised by H.H. Schultz and J.Q. Sherman in 1932. The world’s first window air conditioner, it was a huge success. However, the cost of this air conditioner meant that fewer units were sold than projected.

As a result, these newer versions became more popular since more people could afford them.

In the 1970s, the first central air conditioning units appeared on the market. However, they were shown to be environmentally harmful due to the usage of freon, an ozone-depleting chemical, in the air conditioners. Since their discovery, AC manufacturers have sought to use less harmful refrigerants.

In the United States, air conditioners are becoming increasingly popular. Around 87% of American households had them installed by 2009, according to estimates.

Parts Of A Window Air Conditioner

To comprehend the workings of a window air conditioner, you must first be familiar with its many parts. Because its very parts are critical to its operation.

This in mind, let’s take a look at the mechanical components of an air conditioning system and the purposes they serve:

  • Refrigerant is moved between evaporator and condensers by a compressor, which is also known as the “heart of an air conditioner.”
  • The fan and the blower of an air conditioner each have a distinct purpose. While the blower cycles hot air over the evaporator to cool it before inhaling the cooled air into your room, the former draws hot air from the room and rejects it to the outside environment.
  • The condenser coils are in charge of reducing the temperature of the hot air that the fan/blower has drawn in from the room.
  • To remove heat and humidity from the air drawn in by the fan, an evaporator coil is employed.
  • The evaporator coil uses chemical refrigerant to remove heat and humidity from the air in your home.
  • The heated air that the air conditioner pulls in from your room contains dust particles, so it needs a filter to remove them. Those particles must be removed by the filter.
  • Your windows air conditioner’s thermostat is the regulator on the room-facing side of the unit, which allows you to set the temperature and flow rate of cold air.
  • Using the idea of throttling, the expansion valve lowers the air temperature between the evaporator and the condenser coils.

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How Does a Window Air Conditioner Work?

A window air conditioner is a type of air conditioner that is put in a window. To chill the space, a fan inside the unit blows air over the evaporator. Cooling the condenser in the window unit is done using a second fan on its exterior.

The Room Air Cycle

Window air conditioners are all about moving the air.

“Room air” refers to the air in your room that is located directly in front of the air conditioner’s cooling coil.

The compressor and blower both kick on simultaneously as soon as the window AC kicks on. As soon as the compressor kicks on, the cooling coil (also known as the evaporating coil) begins to cool.

The blower draws up hot, dusty air from the room and passes it through the air filter, removing the undesired material.

Your cooling coil is next in the path of the air.

This is a two-way street:

For starters, because the coil is considerably cooler than the surrounding air, it absorbs the heat, resulting in a drop in the temperature of the space and a corresponding “cooling” effect.

Second, because the cooling coil is cooler than the room’s dew point, condensation forms on its surface.

Reduces air relative humidity by removing water vapor from the atmosphere.

As the air is drawn in, it is “exhaled” at high velocity through a metal duct before being blown out of the AC’s front panel.

As a result, the air in the room is pushed in and cooled, helping to maintain a low temperature and humidity.

In the end, things will change.

The air in the room contains more moisture and is hotter than the air that has been cooled, therefore those characteristics are transferred to the fresh air.

That means the blower pulls it back in and the cycle begins again.

The Hot Air Cycle

Understanding how window air conditioners function is also critical to a thorough understanding of the hot air cycle.

The condenser is cooled by exterior, or “atmospheric,” air in this cycle.

The condenser, then, is what?

AC’s condenser is located outside of the room.

The condenser’s propeller fan draws in high-temperature air and blows it right over the condenser, which is exposed to your exterior atmosphere.

However, the condenser itself is filled with refrigerant, but it is at a dangerously low temperature.

Before anything can cool, it needs to be cooled down.

Even if the “atmospheric” air is already quite warm, the heat absorbed by the condenser causes it to rise even further.

Observe for yourself how hot it is behind a window air conditioner.

The cycle’s name derives from the volume of hot air it produces.

The refrigerant enters the expansion valve and then the cooling coil after it has been cooled.

As the heated air mixes with the surrounding atmosphere, it is forced over the condenser, where it is absorbed and recirculated.

In this way, the flow of hot air is maintained.

What’s the Thermostat Do?

In order to comprehend how a window air conditioner works, it is important to know this.

Even the smallest room coolers are equipped with a thermostat.

The more costly AC units for windows have digital controls, while the less expensive ones have rotary dials.

A desirable room temperature equilibrium is achieved regardless of how it is set.

A thermostat stops the compressor when it recognizes that you’ve achieved your target temperature.

When the temperature in the room rises again, the thermostat lets go, reactivating the compressor and starting the cycle all over again.

Keeping this in mind, lowering your thermostat won’t speed up the process of cooling down.

It’s nothing more than a timer that informs the device when to shut down.

How Room Air Conditioners Work - HomeTips

Adjusting Air Speed

The blower fan, on the other hand, has a speed that you can set.

It’s a blower fan, though, that has a variable speed.

Blower fan speed can be controlled, on the other hand.

If you’re becoming too hot in a room, it’s a wonderful thing to look at.

The Function of Air Filters

Dust is drawn into the room by the blower, as we described at the beginning of this article.

Because window air conditioners come with an air filter, you won’t have to worry about any of that.

Every few weeks or so, these need to be cleaned.

The filter gets blocked if you don’t do this.

Filters that are clogged allow dirt to enter the evaporator coil, causing it to get choked.

A professional evaporator coil cleaning or a new AC unit are your only options if this happens to your AC system.

It only takes a few minutes of your time to clean the air filter, but it’s well worth it.

If you take care of it, your window air conditioner will continue to offer you with comfortable cooling for many years.

The Importance of a Good Window

You shouldn’t skimp on the quality of your window because a window air conditioner can only be mounted on a sill or ledge. It would be a waste of money to buy a new window air conditioner only to have it break because your windows aren’t strong enough to support it.

In most double-hung windows, window air conditioners will fit. There are normally two functioning sashes in double-hung windows. Some window air conditioners are not suitable with sliding or casement windows, so you’ll have to be a little more selective when purchasing one.

Milgard is the only name you need to remember when it comes to windows that are built to last. When it comes to providing the best service possible, US Window & Door has been chosen as Milgard’s preferred vinyl window dealer in San Diego because of our dedication. Southern Orange County is also included in our service area.

Many options are available from Milgard Windows & Doors to meet the needs of all customers. With Milgard Windows & Doors, you may replace windows that don’t allow your air conditioner to function properly. If you’re building a new house, their services are also readily available, and you’ll want windows that look great with your new home.

Confused by the window lingo and unsure whether vinyl, aluminum, or fiberglass is the right choice? Milgard Windows & Doors provides consultation services to help you choose the finest window type for your home.

Milgard also offers a lifetime warranty, so your investment is safe! See what San Diego and Southern Orange County homeowners have to say about Milgard’s goods in their online reviews. With Milgard, you can expect nothing less than the best.

The Benefits of Window Air Conditioners

What are the advantages of window air conditioners, now that you understand how they function and the need of a robust window?

♦ Window air conditioners are economical and easy to install

As previously said, window air conditioners are significantly less expensive than traditional AC systems. The cost varies from one model to the next based on the features and the manufacturer. However, for as little as $100, you may locate a product that does its job and provides obvious effects.

The installation of these devices is also pretty simple, as you don’t necessarily need an expert to perform it for you. Manuals for most of them are simple to follow.

♦ They consume less energy

Window air conditioners are extremely energy-efficient, saving you money in the long run. When shopping for one, search for one that has been certified by the Energy Star program.

♦ They are portable

As a result, window air conditioners are portable in the sense that they may be unhooked and taken with you if you decide to relocate. The central air conditioning unit, for example, is a permanent AC system that cannot be relocated from one home to another.

♦ They are multi-purpose

Heating and cooling functions can be found in many window air conditioners. As a result, you can use them throughout the year to keep your house at a suitable temperature.

♦  They don’t occupy floor space

Since window air conditioners must be placed near the window, they save floor space.

How To Increase The Efficiency Of Your Window Air Conditioner?

In order to improve the performance of our window air conditioners, experts have provided us with the following advice:

  • It’s easy to forget to clean the filters on a regular basis, despite the fact that it’s a simple task. Pollen, dust, and dirt get trapped in the filter and if they aren’t cleaned, the air conditioner’s effectiveness suffers. This can’t happen.
  • The air conditioner’s coils aren’t just responsible for moving cool air in and hot air out; they also collect dirt and dust. Embedded filth can be removed with an old toothbrush, while visible surface material can be removed with a moist towel.
  • If your window air conditioner isn’t level, condensation won’t be able to flow out of the back as it should, reducing its performance.


Window air conditioners are one of the most cost-effective and easy-to-install ways to cool a single room.

When compared to split or central air conditioning units, their starting prices are exceptionally low, and they can also keep your room cool for longer durations.

If you have any questions about how they operate, please don’t hesitate to get in touch.