- by Martijn Koelewijn, 25/11/19
Did you know that 11 of the world’s 30 largest cities are in the tropics?
A Heinen & Hopman commissioning engineer told me about an interesting experience he had in one of those cities that made me think. As he walked back to his hotel on a hot, damp night, he suddenly became aware of a sound. It was a discreet background noise at first, like the chirping of crickets.
But he soon realised it was the humming of air conditioning units all around him.
This is the story that inspired this article, which looks at the impact, especially in demographic terms, that artificial cooling has had on the world.
First there was nothing. Only provisional cooling using snow and ice cubes brought in from colder areas. This was transported in boxes lined with sawdust, and usually melted to a fraction of the original mass by the time it could be used.
Then a breakthrough came in 1902.
A lithographing and printing company in New York City was looking for a way to eliminate variations in humidity levels while printing in colour. The young engineer Willis Carrier came up with a solution which circulated air over coils that were chilled by compressed ammonia to maintain a constant humidity. And while the original purpose of the machine was not cooling but dehumidifying, its potential as an artificial cooler quickly became apparent.
The new air conditioning technology was soon deployed widely. First it was used in public buildings like theatres. These where often shut down in summer because of the absence of windows, the presence of many people packed tightly together and the heat emanating from lights made them too hot. Shopping malls were next.
As artificial cooling conquered America, it provided new demographic opportunities. People could move from the northern states to the previously too hot south of the country. After 1920, the proportion of the US population living in the Sun Belt – southern states from Florida to California – grew from 28% to 40%.
Soon, residential air conditioners were being used all over the globe. Dubai, which grew from 20,000 residents in 1950 to 2.8 million today, is an extreme example of a place that owes much to this technology.
Air conditioning doesn’t just give us a comfortable environment: it also provides a technological advantage. Computers fail if they get too hot. Data centres are filled with air conditioning units that keep the hardware cool and protected from moisture.
People are more productive in cooler environments. Students score lower on tests if the temperature during an exam exceeds 22°C.
Still, there is a downside to all the comfort. Remember the commissioning engineer walking the city at night who heard the humming of thousands of AV units pumping the heat out of the buildings into the environment?
Making it cooler inside, we make it warmer outside.
As good as we are at climate control inside buildings, we have no control of the outside climate. We can’t make it rain on fields of crops or make the sun shine over vineyards.
Martijn Koelewijn | Project Manager
Martijn Koelewijn has been working at Heinen & Hopman since 2006. Starting out as an intern in the workshop followed by a function as draftsman, he gained valuable HVAC experience in the maritime industry. Martijn later worked his way up to project engineer and worked as a project coordinator in Germany before he moved to Brazil to manage Heinen & Hopman Brazil for five years. He returned to our headquarters in 2018 and since then has been working as a project manager for various navy projects.