Updated at: 15-03-2023 - By: Sienna Lewis

During the summer, your home may become unbearably hot. Window air conditioners are something you’ve probably seen before. Are you always aware of what they are and how they function? Warm air and humidity are removed from the room as the air conditioner blows air out the window.

Many homes have them because they are more affordable than other forms of air conditioning, such as a central air system. Stay with me if you’re interested in learning the ins and outs of how they function and the advantages of having one installed in your own home. With the information in this article, you’ll be able to use a window air conditioner effectively and keep your home comfortable even in the hottest months of the year.

What is a window air conditioner?

The most basic kind of air conditioner is a window model. You can think of it as a whole because all of its components fit neatly inside a single housing. This form of air conditioning is typically installed in a window and connected to a standard wall socket. It’s practical because you can put it in any window you want and it won’t interfere with your HVAC system.

How Room Air Conditioners Work - HomeTips

History of Window Air Conditioners

Several key discoveries in the 19th century laid the groundwork for the field of air conditioning science. Among the many noteworthy contributions, one by a doctor named Dr. John Gorrie stands out. For his patients with malaria fevers, Dr. Gorrie built an ice-making machine in 1840.

These kinds of innovations were looked down upon at the time. A machine that could supposedly “change” the temperature was seen as a heinous concept. Many people felt that such actions were blasphemous because they represented a meddling with Mother Nature.

In 1902, Willis Haviland Carrier, the “father of modern air conditioning,” invented the first air conditioner. In order to cool down the Brooklyn offices of the printing firm Sackett-Wilhelms Lithographing and Publishing Company, he devised an air conditioner. It was necessary to install an air conditioning system because the high temperatures in the printing plant caused the printing paper to wrinkle and the ink to spread unevenly.

It took some time for people to start using air conditioners because of how cumbersome they were. The fact that they were extremely expensive added insult to injury. Smaller, more domestic air conditioners began appearing in the 1930s.

Engineer Henry Galson later developed a more space- and cost-efficient window air conditioner.

H.H. Schultz and J.Q. Sherman invented the window air conditioner in 1932. The first ever window air conditioner was created by this revolutionary idea. This air conditioner was still quite expensive, which led to lower than anticipated sales.

Thankfully, more people were able to buy these newer models when they became available.

In the 1970s, the first central air conditioners appeared. However, it was found that the refrigerant used in the air conditioners, known as freon, was harmful to the environment. Since then, air conditioning manufacturers have worked to find ways to use more eco-friendly refrigerants in their products.

Air conditioning systems are increasingly common across the United States. It was predicted that by 2009, nearly 90% of American homes would have them installed.

The Basics

It’s easy to see why the window AC is so popular. The most cost-efficient method of cooling a home is with window air conditioners. These are also not too difficult to set up, so they won’t be too taxing on your back.

A window air conditioner’s cooling effect is the result of the device sucking the hot, humid air out of the room and releasing it outside. Air conditioners for the windows are typically installed on the windowsill so that the warm, humid air can be exhausted outside.

We’ll go over the main components of a window air conditioner and the functions they serve in greater detail so you can get a feel for how these machines function. Compressor, condenser coil, evaporator coil, thermostat, fan, blower, filter, and filter box are the main components of any window air conditioner.

Both the filter and the thermostat work together to keep the air conditioner running smoothly by removing dust and other particles from the air before it enters the system. Together, the fan and blower draw in hot air and force out cool air into the room.

As hot air enters an air conditioner, its temperature is lowered by the condenser coil. However, the evaporator coil, also known as the cooling coil, removes the heat and humidity from the warm air. To put it another way, the refrigerant is the glue that keeps everything together and the compressor is the motor that keeps it moving. Without it being discovered, we would still be in a lot of pain every time summer rolled around. As the refrigerant is pushed by the compressor, it changes phase from liquid to gas and produces the desired cooling effect.

Now that we have a thorough understanding of each component’s role, we can put together the pieces to form a complete picture of how window air conditioners work. Both the room and hot air cycles are necessary for a window air conditioner to function. The window air conditioner’s hot air cycle describes how the unit cools itself, while the room cycle explains how it cools the room.

Service Provider of Window AC Repairing Service & Split AC Repairing Service by Star Cool Service, Mumbai

♦ The Room Cycle

As the name implies, indoor air is used in the room cycle. When the thermostat senses an increase in temperature, it does two things in response. The warm, muggy air in the room is first sucked into the AC by the blower. Second, the compressor kicks on and cool refrigerant flows through the evaporator or cooling coil.

Because the air that is drawn in is typically full of dust and other particles, it must first be filtered. This procedure is essential because it eliminates the dust in your room. Once this is complete, the air is directed over the coil.

The cool refrigerant flowing through the cooling coil keeps it consistently cooler than the surrounding air. That’s why it can use the warm air that’s been filtered into the room. Humidity in the air decreases when the temperature of a room drops. This drawn-in air is cooled and dehumidified before being blown back into the room at high speed.

The cycle continues as the cooled air mixes with the hot, humid air in the room, which is then sucked back into the air conditioner by the blower. The result is a relaxing and soothing ambiance in the room.

♦ The Hot Air Cycle

In contrast, the condenser in a hot air cycle is cooled by outdoor air. The condenser of a window air conditioner is housed in the exterior unit. Because of this, it is subjected to the heat of the atmosphere and requires cooling.

In this case, the hot air is sucked in from the outside by a fan. The condensing coil is then exposed to the hot air. Through the condensing coil, the refrigerant flows at a high temperature. It enters the air conditioner already heated up, then travels over the condenser coil, which raises its temperature even further. The term “hot air cycle” describes this phenomenon because of the buildup of heat. If you’ve ever pondered why window AC units get so hot behind, now you know the answer.

The refrigerant must be cooled before it can begin to cool the hot air that has been drawn into the air conditioner. As the gaseous refrigerant moves through the expansion valve, its pressure and temperature decrease. Therefore, the air converts it into a liquid at a lower temperature, thereby cooling the condenser. As the liquid refrigerant moves to the evaporator coil, the cooled air is vented to the outside. As a result, fresh hot air from the outside is drawn into the AC unit, and the process repeats itself.

The Importance of a Good Window

Considering that window air conditioners have to be mounted on a window sill or ledge, it’s important to get a good one. If your windows aren’t strong enough, your new window air conditioner will likely fall out of the window and break.

Double-hung windows are the standard and work well for most air conditioners. Two movable panes, or “sashes,” that can be raised and lowered make up a typical double-hung window. Some window air conditioners are not designed to work with sliding or casement windows, so keep that in mind when shopping.

Window shopping stops here with Milgard because they are the best in quality and durability. US Window & Door is pleased to be Milgard’s premier certified dealer for vinyl windows in the San Diego area because of our commitment to providing superior service. Southern Orange County is also covered by our services.

When it comes to windows and doors, Milgard has a wide selection to meet a wide variety of needs. Milgard Windows & Doors has excellent replacement windows if you already have them and they don’t work with your air conditioner. If you’re building a new house and want windows that will really make your home stand out, they’re also easy to get in touch with.

Need help deciphering window terminology and making a decision between vinyl, aluminum, and fiberglass? If you’re having trouble deciding which window style would be best for your home, consult with the experts at Milgard Windows & Doors.

Your investment is extremely secure with Milgard because of their unbeatable lifetime warranty. Check out the positive feedback left by San Diego and Southern Orange County area homeowners on online review sites about the quality and longevity of Milgard products. Milgard guarantees that you will receive nothing less than superior quality.

The Operation Of A Window Air Conditioner

Despite its simple appearance, this device contains a number of intricate parts that work together to improve the indoor air quality. It’s fascinating to watch this machinery carry out the entire process.

We take a look at our air conditioner and assume that its sole function is to keep the room at a comfortable temperature. However, they perform a wide variety of functions, and this fact alone should pique our interest. Therefore, we should indulge our natural curiosity and inquire as to its workings in their entirety.

So, without further ado, here’s the skinny on “Window air conditioner how it works.”

Window Air Conditioners Buying Guide

Process #1. Circulation of room air

This process, which occurs on the inside of your air conditioner, involves dehumidifying and cooling the space. Where and how does it begin, though?

The compressor and fan will run on electricity when you turn on the air conditioner. The next step is for your blower to begin sucking in your room’s warm air; after it passes through your air filter, the air will be purified.

The evaporator coils will be exposed to the filtered air. Due to the higher temperature of the air above the circuit, condensation will occur.

And this new, colder product incorporates the sucked-in air. Whereupon the ventilator will release the air through the opening in the front panel. Due to the cyclical nature of this procedure, it will keep repeating itself until you turn off your air conditioner.

Process #2. Purpose of air filter

The air filter is an integral part of the system that we discussed earlier. The filter in the air conditioner will catch all the dust and debris floating around in the air before letting it out into the room.

If you don’t have one, the dust and dirt could get into your air conditioner’s moving parts and cause it to malfunction. Accordingly, once every two weeks is the recommended frequency of cleaning.

You also don’t want the filtered dust to be released with the air from your air conditioner. In addition, it will help to improve the quality of the air in your home and make the ventilation system more dependable.

Process #3. The cycle of warm air in the exterior side

As its name implies, this procedure involves the exterior of your air conditioner. It is the condenser’s job to cool the refrigerant, so that is where the emphasis lies.

Also, you’ll have to contend with the environment’s hot air. This is why touching the back of your air conditioner causes a warm sensation.

Your air conditioner uses outdoor air to cool the interior by way of a propeller fan located close to the condenser. Unfortunately, the air is usually absorbed.

When air is sucked into a condenser, it draws away heat, increasing ambient temperature.

But the condenser has been cooled, so it can do its job and reduce the temperature of the refrigerant. Next, the coolant flows to the valves and coils. And the revolving door never stops turning.

Process #4. Thermostat adjustment

A temperature control is standard on all air conditioners. It’s possible the remote or the unit itself is at fault. Despite these variations, your air conditioner’s output temperature is still controllable.

Every time you start to feel hot, you turn down the thermostat. Yet, as the hours go by, you begin to feel a chill, forcing you to keep adjusting the temperature until you reach a state of contentment.

When the thermostat is adjusted, both the indoor and outdoor air cycles are affected. In some cases, the condenser may cool more refrigerant than the evaporator. Alternatively, more heat can be extracted from a room and cooled air produced.

Please be aware that changing the thermostat does not speed up the cycle, but that other factors can. The numbers on your window air conditioner’s temperature controls indicate the degree of chill you’ve selected. However, these digits are used by some to denote the timer.

Process #5. Fan intensity

Your thermostat’s controls include both temperature and fan speed. This mechanism is what accelerates the cooling of your room.

Controls allow you to adjust the speed of the fan to your liking. Increase the rate, and the cycle will repeat that much more quickly. More air would be expelled by your air conditioner as a result.

You can feel all the cold air rush into your face if you stand next to the front panel, which is the best part. During the warmer months, this is a common occurrence.

How do you pick the right window AC unit for your home?

In selecting a window air conditioner, size is of paramount importance. If the unit is too small for the space, it will have to work harder than necessary to achieve the desired temperature, and the result will be an uncomfortable room. Having a cool room that still feels sticky is the result of an air conditioner that is too large for the space.

Consider the area that needs to be cooled by the window air conditioner. One square foot of space requires 20 BTU (British Thermal Units; a unit of cooling capacity) from a window air conditioner. Multiply the room’s length by its width, and then multiply the result by 20. It should be enough BTUs to cool the area. Always exercise caution when deciding which window to install the unit in. The effectiveness can also be affected by things like the size of the window, where it is situated in the room, and the weather outside. Examine the role that the weather can play.

Add a window air conditioner if your home gets too hot during the summer or if you need additional cooling beyond what your central air conditioning can provide. If you need help deciding which air conditioner is best for your home based on factors like square footage, price, and energy efficiency, contact the pros at Aire Serv Heating and Air Conditioning.

You may be debating whether or not it is worthwhile to repair that broken appliance. Don’t be perplexed any longer; Mr. Appliance has some answers for you. Mr. Appliance, along with Aire Serv, is one of the home service providers that makes up the Neighborly® family.

The Benefits of Window Air Conditioners

What are the advantages of window air conditioners now that you understand how they function and why a strong window is required for them?

♦ Window air conditioners are economical and easy to install

As was previously stated, window units are less expensive than central air conditioners. Pricing varies by model and manufacturer. You can get one that does its job and produces visible results for as little as $100.

Not only are these units simple to set up, but in many cases, a technician isn’t even necessary. You can usually find user guides that are straightforward online.

♦ They consume less energy

In comparison to central air conditioners, window units have a low energy footprint and can help you save money. One thing to keep in mind when looking for one is to prioritize finding one that has earned the Energy Star label.

♦ They are portable

It is simple to disconnect a window air conditioner from its mounting and transport it to a new location. Central air conditioners, for example, are built into each home and cannot be taken with the homeowner if they decide to sell.

♦ They are multi-purpose

Many window air conditioners can be used as heaters as well as coolers. In other words, you can use them to keep your house at a comfortable temperature throughout the year.

♦  They don’t occupy floor space

Given that window air conditioners are designed to be installed next to windows, you won’t have to sacrifice any floor space to accommodate them.

5,000 BTU Window Air Conditioner - TAW05CM19 | TCL USA


After their invention in the 1930s, window air conditioners quickly became ubiquitous in American homes. They can serve multiple purposes, consume little energy, and are easy to set up.

Depending on the features they offer, they also come in a wide variety of sizes. Even in modern times, improved window air conditioner models continue to be released. Improvements in energy efficiency are at the heart of most of these changes.

It is important to note that a solid base is necessary for these air conditioners. Only a sturdy, dependable window will allow your window AC to perform at its highest level. The windows offered by Milgard Windows & Doors, a well-known company in the United States, are known for their high quality, durability, strength, and adaptability. Visit us at US Window & Door if you’re in the San Diego or Southern Orange County areas, and we’ll show you how to get the most out of your home’s vantage point all year round, whether that’s by keeping the heat out or letting in the fresh air.

It seems likely that window air conditioners will remain in use for the foreseeable future.