Nowadays we take the modern air conditioning unit for granted – on a hot day in the office or in our homes we simply flick the switch, and we are rewarded with a pleasant breeze of air, cooled perfectly to our chosen temperature. The man we have to thank for this modern innovation is the American inventor Willis Carrier, who in 1902, came up with this world changing invention…
When a printing company in Brooklyn were having problems with the humidity of the air in their factory affecting the quality of the paper that they produced, Willis Carrier set about coming up with something that would solve this problem for them. He came up with the air conditioning system – the design which modern air conditioning systems are still based on – and solved the problem for the print company.
By moving the hot air out of the room and pumping it outside, whilst air that is pumped back in through a copper pipe like this https://watkinspowis.co.uk/products/copper-pipe-fittings-and-press-systems/ then pumps air into the compressor where a chemical called the refrigerant cools the air and pumps it back into the room.
This idea was not surprisingly a huge hit, and it was such as success that it was not just American companies that wanted to purchase an air conditioning system for themselves, it was companies all over the world. From preserving historical artwork, to keeping theatres and cinemas cool and comfortable, air conditioning has completely changed the way that we can operate for the better.
Looking after a modern air conditioning unit
Carrier’s invention has become an everyday appliance, but like any machine it needs regular care. A unit that is neglected can break down when it is needed most and lead to expensive repairs, while one that is looked after runs smoothly, keeps rooms comfortable and costs less to run.
A good starting point is to get to know the main parts of your system, such as the compressor, the thermostat and the refrigerant circuit, so you can describe any fault clearly. The circuit breaker settings matter more than they might seem and should be handled with care, since an electrical problem can stop the whole system.
The level of refrigerant is another thing to keep an eye on. When it runs low, the unit struggles to cool properly and has to work harder. If cooling seems weaker than usual, having the levels checked by a qualified engineer is a sensible step, particularly for a unit that is in heavy use.
How air conditioning systems differ today
The systems that grew out of Carrier’s invention have become far more sophisticated. Modern units use their energy much more efficiently and are designed to keep a space comfortable throughout the whole day rather than simply blasting out cold air.
There are two broad types of system. Central air conditioning is usually installed in large buildings such as offices and hospitals, where cooled air is distributed through a network of ventilation. Smaller distributed systems are designed for apartments and houses, cooling individual rooms or areas instead of an entire building.
Whichever type is fitted, an air conditioning unit needs servicing at regular intervals. Periodic checks keep it running at its best, help it use energy efficiently and make sure it carries on delivering the comfortable indoor climate that Carrier set out to create.
Cooling rooms before Carrier’s invention
Long before 1902, people understood that moving air made a hot room bearable. The difficulty was doing it on any useful scale. Heating came first: at the turn of the century, systems that blew warm steam into a room were seen as the answer to keeping buildings comfortable in cold weather.
Carrier’s leap can be seen as a piece of reverse engineering. Instead of passing steam through the system, he ran cold water through the coils, so the air coming out was cooled rather than warmed. That simple reversal is the root of every air conditioning unit in use today.
Before it, keeping cool relied on muscle. In the days of the British Raj, colonial households refused to give up their heavy tweeds and corsets despite the heat. Instead they employed servants to pull constantly on a large wooden fan hung above the dining table, wafting air over the diners for as long as the meal lasted.
