Most people are already familiar with air conditioning as a way to cool air in our workplaces, shopping centers and homes. However, you might be a little less aware of exactly how the technology works.
Air conditioning (also often referred to simply as aircon or AC) is an essential part of life in many warmer climes and provides relief from excessive heat. If you run an office or store, it’s quite likely you already have aircon installed for the comfort of your staff and clients.
A brief history of air conditioning systems
American inventor Willis Carrier is widely accredited with inventing the first aircon unit back at the turn of the last century. Despite this, aircon’s very earliest and most basic origins actually span as far back as the ancient Egyptians who used to hang water-dampened reeds in windows to generate cooler air.
Carrier had already been working at ways to heat air with steam and used this knowledge to create the opposite – a way to cool otherwise hot air. His first commercial unit was released in 1902 and began to grow in popularity, mostly used in industrial settings. By the 1940s the system was refined to make smaller units that could be mounted in windows – leading to the mass take-up of aircon for residential use.
The processes involved in air conditioning in most units
At its simplest, air conditioning works in a very similar way to the common domestic fridge. Heat is transferred from inside your home to the outside using a cooling agent called a refrigerant. This refrigerant passes through a closed coil system, essentially pushing the hot air outside and replacing it with colder air, cooled inside the unit.
At the heart of most air conditioning systems lies a scientific phenomenon known as phase conversion. Phase conversion takes place as liquids change form to become a gas. During this process, these liquids also have the ability to absorb heat. This constant evaporation and condensation process is what serves to draw the heat out and pump freshly cooled air back in.
No matter the size of the unit – from the simpler aircon machines we see in homes to much larger industrial air conditioning systems, these same basic cooling principles remain the same in almost all aircon devices.
The most common types of air conditioning systems
By far the most common type of air conditioning you’ll see in use are the units attached to the windows of residential homes. However, there are a few other types that could be worth considering, depending on your particular requirements.
Window units: As mentioned above, positioned in the window units of homes. These units tend to be the least expensive – but will only be effective at cooling smaller spaces. They can also pose a security risk if installed on ground floor windows.
Central air conditioning: Used to cool bigger houses or apartments where you want to cool more rooms at once.
Portable air conditioning: Similar to window units, portable aircon devices have all their components built-in but also offer portability. The hot air is typically vented through a pipe, using a special kit that attaches to a window.
Through-wall aircon: Typically fitted in situations where the owner doesn’t want to compromise the use of a window.