It has certainly helped make the world more productive. The economist William Nordhaus found in 2006 that the hotter the climate, the less productive its people; a study of US government typists in the 1950s found that typists do 24% more work if temperatures are kept low. Thanks to air con, the economic benefits of being cool have today been spread across the globe. The world economic system now depends on it. Factories, offices and the server farms that power the internet all rely on air conditioning. Furthermore, its health benefits are indisputable. Recent decades have seen a dramatic decrease in the number of deaths during heatwaves in the US, and the strongest protective factor, as one study found, was “a working air conditioner”. By filtering and dehumidifying the air, it also improves many respiratory and skin conditions.
So what’s the downside?
The scientist Stan Cox, in his book Losing Our Cool, blames air con for “resource waste, climate change, ozone depletion and the disorientation of the human mind and body”. It emits some half a billion tonnes of CO2 annually, and the coolants used are even more polluting than CO2. Air conditioners fuel a vicious cycle: they pump out heat, making the outside world hotter still. One study found that air conditioners increased the temperature of Phoenix, Arizona on summer nights by 2°C. An air conditioned society, complains Cox, has fewer free communal spaces and more commercialised indoor venues such as shopping malls. It has also ended traditions such as the siesta, and condemned its users to what one critic calls “thermal monotony” – a global standard of 22°C (incidentally, a level calibrated to suit men, who have a higher metabolic rate than women).
What is the future for Air Conditioning?
The evidence suggests the market will continue to grow inexorably. However, the hope is that architects and designers will become less wasteful in their use of air con: “passive cooling”, for instance, keeps temperatures low by non-mechanical means, such as using insulation, natural ventilation and reflective surfaces. Japan’s Cool Biz campaign, meanwhile, encourages businesses to raise workplace temperatures from 22°C to 28°C, and to allow staff to wear shorts and polo shirts. Air con has its critics but, as The Economist remarked, it uses far less energy than heating – “the necessity of which is seldom contested”.
The Science of Keeping Cool
Humans have known how to make fire for at least 100,000 years, but making cold is a very modern skill. Modern refrigeration, though, is only an enhanced version of what happens when water evaporates: when a liquid turns into gas, heat is borne away with it. In the early 19th century, scientists discovered that if you used volatile liquids such as ether or ammonia, the process could be supercharged. This is what happens in the loops of a refrigeration cycle. Whether in a fridge or an air conditioning unit, a volatile coolant is compressed into a liquid state then forced to evaporate inside the unit so that it absorbs a large amount of heat. Next, it is pushed out of the unit where it is mechanically condensed so it expels the heat. The liquid then cools and re-enters the unit, starting a new cycle.
The technology was first used to make ice in the 1850s. Refrigerators followed in the early 20th century. Coolants like ammonia and sulphur dioxide are poisonous and so they were replaced by safer chlorofluorocarbons (CFCs), which heavily depleted the ozone layer. They were banned and replaced by hydrofluorocarbons (HFCs) and other coolants – ozone-friendly, but greenhouse gases nonetheless.
Air conditioning doesn’t just cool you down, it will also improve the quality of air around you. This leads to many benefits, some of which include respiratory conditions, the health of electrical equipment, work efficiency and general physical health. As well as these benefits, air conditioners will eliminate pollutants and contaminants including pollen and dust mites from the air. You must ensure to look after and service your air conditioner regularly to maximise its effectiveness!
In the hotter months of the year, when you walk into a room with air conditioning, you should notice it is easier to breathe, especially if you suffer from hay fever, asthma or any other respiratory problems. There are a couple of reasons for this, firstly a room without air conditioning is likely to have the windows open causing harmful particles such as pollutants, dust and smoke to flow into the room. A large number of pollen particles in the air are very common in summer. With an air conditioner, these pollen particles will likely get trapped in the filters (as they are quite large in size), therefore stopping them from flowing into the room, this includes any other larger particles that could be an irritant to your system. The quality of air is cleaner and less harmful within an air conditioned room.
When the humidity of air is lowered (which is what occurs when we use air conditioning to cool a room) it decreases the chances of mould and other fungi growing, as they prefer drier, more humid environments. Not only does this save time having to clean up, but it also means bugs such as cockroaches, mould mites and termites aren’t attracted to the fungus free room! Like we mentioned above it is important that you get your air con serviced and cleaned regularly to prevent this type of growth.
It is proven that we all concentrate more productively when working in comfortable temperatures rather than in boiling heats. The recommended temperature in a working environment should be anywhere from between 16 degrees to a maximum of 25 degrees. When the temperature rises to 27 degrees and above, work productivity significantly drops, likewise when the temperature drops below 14 degrees. BBC wrote that the best temperature to maximise performance would be around 22 degrees, but of course, this varies from person to person. If you are currently opening the window to encourage fresh air flow into the office, it could be quite noisy outside, therefore distracting you from working properly, whereas air cons are practically silent. Not sure mention that you feel the fresh air from an air con pretty much as soon as you turn it on, whereas it may take a while to feel any airflow if you have just opened the window.
It is not uncommon that computers and machinery can overheat in the summer months, causing them to shut down and make you lose all your work. Air conditioning can help with this problem. It is, of course, more likely this would happen in places such as a server room or anywhere with lots of machinery and computers, but there is definitely a good chance of a computer shutting down in a room with no air conditioning versus a room with air conditioning.
Other benefits of installing an air conditioner, are that you are less likely to have a heat stroke, you will sweat less meaning you won’t lose as much water from your body, which could potentially lead to dehydration. Air conditioners are also likely to filter out any flus or viruses that could have otherwise been spread around the building. And finally, having an air conditioner (whether it be a portable or fitted) in your room on a hot summers night will almost certainly help you get to sleep faster!