How Air Conditioners Work
A Brief History
The first air conditioning unit was developed in 1902 by Willis Haviland Carrier, an electrical engineer, to help solve the moisture problem that was being experienced in a publishing company.
In a very short time, the technology was adopted by theatre halls and stores to reduce the temperature during hot summer months.
As you read this, the air conditioning (AC) unit is an integral part of all homes across the globe.
How Your AC Keeps your Home Cool
Basically, the AC unit works like a refrigerator. The major difference is that the air conditioner does not have the exterior housing for insulation as seen in a refrigerator; instead, the walls in your home are the ones that keep the hot air out and the cold air in.
The air conditioner makes use of a major law of physics to achieve its purpose in your home. When a liquid is converted to gas (phase conversion), it ends up absorbing heat.
The AC unit uses special compounds (refrigerants) which evaporate and condense in a closed system of coils to absorb the heat from the surrounding air.
These compounds possess the unique property of changing at low temperatures.
The AC unit also comes with fans that blow warm air over the coils filled with the refrigerants. Additionally, the system also has ducts that funnel warm air to the coils and chilled air away from the air-chilling coils.
When hot air passes over the air-chilling coils (also called evaporator coils), the refrigerant material changes from liquid to gas, therefore absorbing the heat from the air. The resulting gas is warm and has to be put under high pressure to convert it into a liquid again.
This step is necessary in order to make sure your AC unit continues to function properly. To achieve this, a component called a compressor is used to put the gas under high pressure, a process that ends up generating a lot of unwanted heat.
The heat that is generated needs to be removed from the unit, and this is done by a fan and a set of coils termed condenser coils. The gas that was put under compression cools and changes back into a liquid, which makes it possible for the process to start again.
How do Different Parts of an AC Unit Work?
The major function of an AC unit is to cool the air in your house. This is not the only job that the AC unit does; it also monitors and continuously regulates the temperature of air in your home using a thermostat. The other job that an air conditioner does is filtration of unwanted particles from your home.
The unit comes with a filter that prevents any particle from entering your home from the external air. They also remove any airborne particles from the air that is circulating inside your house. Air conditioners also work as dehumidifiers.
They do this by reducing the temperature of humid air that makes it release the moisture contained in it. You must have noticed that on humid days, the air conditioner discharges water. The AC unit comes with two categories of components: those that move air indoors and those that remove air from the indoors.
Essentially, the AC unit consists of three major parts:
The compressor and condenser are found outside the home while the evaporator is usually inside. Several pipes and chemicals are used in conjunction with the three parts to pump in cool air and move hot air outside. The refrigerants easily convert from liquid to gas to facilitate absorption of hot air.
The resulting gas passes through the compressor, which puts it under great pressure before being channeled into the condenser. The condenser comprises of metal fins that help spread the heat. This process cools the gas and converts it into a liquid state. This liquid is much cooler than when it entered the condenser. A small opening connects the condenser to the evaporator.
This small opening is narrow and forces the liquid to pass through which reduces the pressure further. In the evaporator, the liquid starts to evaporate to form gas. While evaporating, it takes heat from the air and passes it over the fins found in the evaporator, which extract more heat from it. The chemical compound is now in form of gas and is taken back to the compressor for the process to start again.
A fan is connected to the evaporator that helps circulate the chilled air inside your home as well as help blow air over the evaporator fins. Since hot air is lighter than chilled air, it usually rises above and is sucked into the air conditioner that is normally situated near the ceiling board of your room.
The hot air that has been taken in moves to through the ducts into the evaporator where it is used to cool the gas contained there. The cool air that remains in the room is circulated around to make the atmosphere cooler. When you buy an AC unit, you get to set the temperature that you need in your home.
The cooling process by the AC unit usually continues until the thermostat measures and detects that the internal temperature is the one that you set. When the thermostat detects that the desired level has been reached, it turns off the AC unit. If the room warms up again, the thermostat will detect the rise in temperature and will turn on the unit automatically for the cooling process to start all over again.
AC units come with a control panel that lets you choose the ideal settings for your home. The selector switch on the panel lets you pick the speed at which the fan will operate. The compressor speed cannot be changed no matter which settings you choose. Several other switches control different features on the AC unit.
A Final Thought
You have to remember that no matter which type of AC unit you have, it needs regular maintenance for it to operate efficiently. Knowing how air conditioners work will help you to pinpoint problems in your unit. Make sure you have a professional mechanic to handle any repairs and servicing you may need.