Previously, air conditioners were luxury items that were only affordable to the rich people. Now, most residential and commercial homes have AC units. Here’s what you need to know about how air conditioners work and the most important parts.
The 5 Main Parts Of An AC Unit
It is also referred to as a coolant. The refrigerant is a special fluid used for cooling and freezing purposes. It works in a closed loop, carrying heat from the inside of the building to the outside. You can think of it as a traveller inside the AC unit. For the proper refrigeration cycle, the refrigerant changes from a liquid to vapour for the most convenient temperatures inside the house.
The refrigerant moves through the cooling tubes and copper coils thereby connecting the indoors to the outdoors. The coolant absorbs heat from your indoors thereby changing from gas to liquid. Next, it goes outdoors and pushes the heat outdoors to allow cooler air indoors. Once the heat is removed outside, the refrigerant changes back to a gaseous state and goes back indoors.
Once the refrigerant is cold again, there is an indoor fan that blows air on the cold coils thereby circulating the cold air throughout the home or office. The cycle repeats every time you have turned on your air conditioner.
2. The Compressor
The main task of the compressor is to pressurize the refrigerant to increase its overall temperature. By following the combined gas law which mentions that if the pressure increases the temperature will follow suit, once the refrigerant is compressed it starts heating up immediately. It happens when the gas is squeezed tightly.
The unit heats up the refrigerant to ensure that the temperature surpasses that of the outdoor temperature. Heat flows naturally from the hotter to the colder bodies. As such, for the heat to be dispersed outdoors, the refrigerant needs to be hotter than the outdoor air. That’s where the compressor comes in handy because it increases the temperature of the refrigerant and the overall temperature.
3. The Condenser Coil
It is found in the outdoor air conditioning unit. The condenser coil receives the high temperature and high-pressure refrigerant from the compressor. It works in the opposite way from the evaporator coil. Note that, the evaporator coil contains the cold refrigerant while the condenser coils contain the hot refrigerant.
The condenser coils have been designed to allow heat transfer to the outdoors. The refrigerant releases heat, thanks to the condenser fan that blows air on the coils. As the heat leaves the refrigerant when it reaches outside, it turns back to the liquid thereby flowing back to the expansion valve. There, it is depressurized and cools down to become gaseous.
4. The Expansion Valve
As the refrigerant t leaves the condenser as a liquid, it disperses the heat. However, it is still too hot to get back into the evaporator coils. Therefore, before the refrigerant is passed to the evaporator coils, it needs to cool down. Here, the expansion valve (which is also referred to as a metering device) comes in handy. It is usually a thermostatic expansion valve.
By complying with the principles in the combined gas law, where if the pressure decreases, the temperature decreases too, the expansion valve works by depressurizing the refrigerant allowing it to cool down. The expansion valve removes the pressure in the liquid forcing the refrigerant to change to gas/vapor inside the evaporator. It also controls the overall amount of refrigerant getting inside the evaporator.
5. Evaporator Coil
These are also very important parts of an air conditioner unit. Here, the AC unit removes the heat inside the residential or commercial property thereby removing it outside. The copper tubes take in the depressurized refrigerant in its liquid form as it passes through the expansion valve. When the indoor air blows on the cold coils, the heat inside your house is absorbed.
It follows the 2nd law of thermodynamics stating that heat flows from hot to cold naturally. The condenser coils require the assistance of the condenser fan to allow heat transfer. Similarly, the evaporator coils need the blower (air handler’s fan) to blow air over the coils. The refrigerant absorbs the heat from the indoor air before it begins the evaporation process to become a vapour.
How Does The Refrigeration Cycle Work?
The return vents which are located indoors, take the hot air inside the house. Next, the refrigerant absorbs the heat present in the indoor air and takes it to the compressor. Next, the compressor pressurizes the refrigerant and heats it up. Once the refrigerant goes through the compressor, it goes through the condenser coils.
The condenser fan which is often big and loud pushes air on the condenser coils to allow heat transfer to the outdoor. Once the heat is released outdoor, the refrigerant goes back through the expansion valve which depressurizes it thereby cooling it down. The cycle repeats with the refrigerant doing the same absorption process over and over again.
Keep in mind that the air conditioner unit in your home goes through these processes when it is turned on. As such, if you leave it on for a long time, it is bound to go through a lot of wear and tear. It’s advisable to turn off the AC when you are not home or when you are not in the room. Even better, regular servicing of the air conditioner allows it to continue working without any issues.