How Does Air Conditioning Work - And How It Can Work For You - 31/10/2018
Stepping off the muggy street into an air conditioned space and feeling the cool, temperate climate has got to be one of modern life’s greatest comforts.
In New Zealand, most of us associate air conditioning with offices, shops, restaurants, cafes and transport. As more Kiwis become heat pump owners, it’s important to understand how heat pumps can double as household air conditioning units - and how air conditioning itself actually works.
What is air conditioning?
Air conditioning may sound like the thing you do after shampooing, or - when abbreviated to air con - like the ‘90s action film starring Nicholas Cage, but when it comes to air conditioning there are no suds or aeroplanes full of criminals to be found.
Instead, air conditioning is a process which removes heat and moisture from air. An air conditioning unit creates and completes this process, often using a fan to then distribute the conditioned air around a designated space.
This space could be an office, car, or home - the desired temperature is then controlled by the machine.
Air conditioning in New Zealand
In New Zealand, while many offices and commercial spaces like shops, restaurants and transport will be fitted with air conditioning units, it is not always common for our homes to be.
This may be for a variety of reasons such as people being at work during the day, the time we spend outside on hot days, and of course affordability. Although New Zealand’s largely temperate climate could also be a root cause of this; we tend to have pretty liveable weather conditions in Aotearoa.
However, in some areas of New Zealand, the climate is much, much more tropical and muggy - and calls for Kiwis to consider their cooling options.
In the upper North Island, especially in Auckland, the summer months tend to be very humid and air conditioning in Auckland can be a great option to keep residents here comfortable in the heat.
Also, as more and more Kiwis get heat pumps fitted to keep their homes warm during winter, and to keep in line with the potential Healthy Homes regulations, the very same units can be used as air conditioners during summer.
How do air conditioners work?
The science of air conditioners stems from the very home of humidity itself; New York City. It was here in the Big Apple circa 1902 that a young electrical engineer needed to solve a humidity problem at a publishing factory.
According to HowStuffWorks.com, the paper in the factory was absorbing moisture from the warm air, making it difficult to apply ink.
The engineer, named Willis Carrier, treated the air inside the building by blowing it across chilled pipes. As the air passed across the chilled pipes, it cooled. Cool air isn’t able to carry as much moisture as warm air, so this reduced humidity in the building and improved the moisture content of the paper. Reducing the humidity also had the side benefit of lowering the air temperature - and a new technology was born.
These days, modern air conditioning units use technology similar to a refrigerator - except your house / work / car is the fridge - and you are the contents. You know those coils you might see in an old fridge? (but are usually hidden away in sleek modern designs), the same type of system is used in air conditioning units.
As Live Science explains, the basic concept of how air conditioning works is that “a chemical called a refrigerant loops from inside the home to outside and back again, absorbing and casting out heat in the process. The refrigerant cools and then re-enters the home, starting the cycle anew.”
Refrigerants change from liquid to gas and back again very easily; each time it makes these transformations it absorbs heat (as liquid) and expels it (as gas). These transformations enable hot air to be turned into cold, just like Willis Carrier blowing hot air across those cold pipes.