HVAC from Antiquity: five age-old ways to keep cool
– Martijn Koelewijn, 05/04/19
What a time to be alive! Climate control – and the associated comfort – is the most natural thing in the world today. It’s second nature for us to use air conditioning in our car, central heating in our houses, and air handling units in our office and on our vessels without thinking. But how did our ancestors manage without climate control? After all, air conditioning was only invented a hundred years ago. What was life like before climate control? Here are five solutions the ancients used.
Persian cooling towers
A cool breeze on a hot day can be very invigorating, don’t you think? Ceiling fans in old hotels certainly have their charm. The Persians were well aware of this, but had no fans at their disposal – so they figured out a way to get air to move by using the forces of nature. They built high towers with openings on the top to catch the wind, which of course blows stronger at higher altitudes. Cool air would be carried down through the towers and into the houses below, the pleasant draft refreshing the inhabitants.
Egyptian air conditioning
The Egyptian desert can be searing hot. Fortunately, in addition to being great pyramid builders, the Egyptians also knew a thing or two about cooling. If you’re familiar with the principles of a cooling machine, you know they’re based on evaporation. In Egypt they used the same concept to cool their houses. They would hang wet reeds in their windows, and as the water from them evaporated, it would pull heat out of the environment, creating a similar effect as a modern cooling machine.
Water is vital to human settlement – living in a dry and sunny land, the ancient Greeks were acutely aware of the importance of living close to sources of water, which they would use for drinking fountains and irrigation of their crops. But water has another interesting quality: its high heat capacity, which makes it an ideal energy carrier for both heat and cold. The Greeks used an innovative piping system that included aqueducts and would redirect cool water from sources into cities, refreshing the surroundings.
The Romans developed a concept called a hypocaust, which represented the first central-heating system. It consisted of a complex of hollow spaces under and around a structure. A furnace in the basement would produce hot air that would circulate in the ducts, heating up the floor and walls. The concept was powered by the fact that hot air is less dense and rises, leading to natural currents of air. This required the ducts to be quite large, so usually only public spaces could be heated with this solution.
Chinese hand fan
Just like the Persians, the Chinese knew that moving air has a cooling effect. But instead of building large towers, they invented something with more mobility: the famous hand fan. This simple tool with a flat surface is waved back and forth to create a flow of air. Their simplicity and elegance – they’re foldable and therefore easy to transport – mean they remain quite popular even today.
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.