How Does Window AC Unit Work & What Are Its Parts?

How Does Window AC Unit Work & What Are Its Parts?

Are you wondering if you should or not buy a window AC unit? Before you finally decide for a purchase you should read about how does window AC unit work and what are its parts responsible for cooling down your room. Especially cooling down big rooms can be complicated – read more about how to cool down big rooms with the best window AC for large rooms.

This kind of appliance is easy and cheap but you maybe want to know more about them. The process of cooling down one room of your home is pretty easy to understand but still very impressive.

Check this article out and explore more about the main function of a thermostat, air filters, and many others. Just keep reading!

Indoor: Cool Air Cycle

Let’s call the air in a room where a window AC unit is located as room air. When you switch on your unit the blower and compressor start to work almost simultaneously. The blower is the first one and a few seconds after it the compressor also gets started. The cooling coil (or evaporator coil) starts to work when the compressor does.

Once the cooling coil is ready for working the room air is sucked into the unit. But the process of sucking is executed at a high temperature of the air while carrying dust and dirt particles. These particles could badly damage your window AC unit and therefore the hot air has to go through a filter firstly.

Before moving to the blower the room air is completely removed from dust particles. Then, we distinguish two processes that happen when the room air reaches the cooling coil.

The first process happens as the cooling coil has a lower temperature than the room air. The heat from the air is absorbed by the refrigerant in a coil. The temperature of the air starts to down crease very fast up to the required value. The air is cooled and apparently fresh.

The second process occurs very soon. It happens when dew appears on the surface of a cooling coil. This is simply a side effect of the temperature of the cooling coil is lower than the dew point temperature of the cooled air. It’s perfect because it helps to remove the moisture from the air and reduce the relative humidity.

The two processes are finished and the cooled air can be sucked by a blower. On its path, the air passes through the metal duct and it’s released into a room through the front panel of a window AC unit. This cooled air keeps the room chilled thanks to two aspects – low level of humidity and low temperature.

As the cooled air absorbs the moister and heat in the room and these two values are increasing the room air is sucked into the unit and the room air cycle repeats again.

Outdoor: Hot Air Cycle

Also, the hot air cycle is a part of the working process of your window AC unit. Therefore, it’s crucial to explain what happens during this phase.

This cycle uses atmospheric air (which is outdoor hot air) to cool down a part called a condenser. To clarify, for room air cycle (indoor) the unit uses only room air and for the hot air cycle, it’s used only hot air from outside of the room (outdoor). The indoor and outdoor airs aren’t anyhow mixed, they are completely separated. The only medium which interacts with atmospheric outdoor air and room indoor air is refrigerant medium.

For further understanding, I need to explain “What is a condenser?”. A condenser is the part of the air conditioner that is in the outdoor part of the refrigerant’s circuit. It is used for condensing refrigerant. The refrigerant changes from air to liquid in the condenser. The condenser is exposed to the external atmosphere (outdoor). The propeller fan sucks in the external high-temperature air and blows it through the condenser.

Usually, the condenser contains refrigerant and at this point, the refrigerant is at a high temperature. For this is used the outdoor hot air which gets even hotter after it goes through the condenser. After this, the refrigerant is cooled down and it becomes the liquid state. Once the refrigerant is cooled down it goes further into the expansion valve and then back into the evaporator (or cooling coil) in cool air cycle (indoor).

At this point, you can understand why AC blows hot air which is much hotter than outside atmospheric air. It can be really hot there – so get enough space outdoor. Because of this hot air “the hot air cycle” gets its name.

Temperature is Set by Thermostat

A thermostat is another crucial part of a window air conditioner and should know how it works and how to operate it. It is one of the main parts, for you, to know how does window AC unit work.

In general, everybody who owns a window AC should set the temperature by using a thermostat. It means if you feel comfortable when the room air has 72 degrees Fahrenheit you should set it on your thermostat. But it’s not so easy in some cases.

The cheap window AC units usually have only a thermostat knob. If you decided for an appliance with a knob you can see some numbers and setting the temperature is easier. Or you can deal with a bar of intensity and the temperature is set by your feelings. To clarify, you can’t set the proper temperature and the indicator, if it’s comfortable or not, is just your feeling. It doesn’t influence the function of the thermostat.

The average or more expensive models usually have digital control. You will be able to set the temperature inside the room on a display properly. This helps to keep the temperature due to numbers not only due to a feeling. Therefore, this kind of temperature control is more precise than the knob part.

It doesn’t matter what kind of control you have the thermostat always works on the same principle. Firstly, you set the temperature the thermostat should work with. Then, it has its parameter and it knows what the desired room temperature is. The window AC unit is checking the ambient temperature permanently and once it’s reached the required value the thermostat holds the compressor of the AC. To clarify, the cooling effect is stopped because the desired room temperature is obtained. Of course, after some time it’s detected that the air temperature increased and it’s necessary to restart the compressor and both cycles to begin the cooling effect again.

Keep in mind to set the thermostat properly to avoid higher bills for electric energy. To set the temperature low doesn’t help the window AC to reach the desired value faster. It simply tells the thermostat when to hold the compressor and its cooling job.

Air Speed Sets the Blower Fan

The window AC unit allows you to set the speed of the air by using a blower fan.

You can set the speed on a remote control if you have it. The fan usually indicates more than one gear. The motor of the fan allows us to change the air faster and also it boosts the cooling effect as the air is flowing faster.

If you come home and need to cool down your body faster increase the air speed of your AC unit. Simply stand in front of the device and let the air cool down you. The air is moving quickly and you feel comfortable sooner.

Air Filter Removes Dirt From Window AC Unit

I have already mentioned the purpose of having an air filter in the AC unit. It helps to remove dust and dirt particles from the air flowing inside the appliance.

The important fact is that you have to clean the filter every few weeks. Why? Because the filter is systematically clogged by dirt particles and the consequence could be a fully clogged filter. Once the filter isn’t able to do its function any more it doesn’t stop the AC unit. The unit still works but the air flowing into the device isn’t clear and the particles of dust and dirt start to get into your evaporator coil and one-day they completely clog it. Once, the unit reaches this state it can’t work anymore. Then, there are only two possibilities. The first one is to pay for professional help to clean the coil the second one is to replace your window AC unit.

Both of the possibilities are expensive and it’s also wasting of money. It’s better to spend a few minutes every two or three weeks and clear the filter precisely. The sweet reward will be a never-ending comfort of fresh and cool air inside the room.

The Bottom Line of How Does Window AC Unit Work

If you are wondering what unit to buy or if so, in general, it’s great to know how does window AC unit work and what the main parts are. You can easily decide and pick the right device which will meet all of your requirements. I compiled the list of the best window air conditioners for you. Also, you won’t be surprised by some things like cleaning filters or cheap kind of temperature control.

The window AC is a very smart appliance and you will be able to obtain a great balance between price and performance. The maintenance isn’t difficult and if you chose the right AC unit and set it properly it will offer you lots of pleasant months during summer.