In the long, lazy hot months of the summer time, ingenious human beings will go to any length to get and stay cool. Our earliest ancestors did not have very many options when it came to getting and staying cool, but the historical record shows that they made a great start of it, by choosing not just the obvious cooling methods – swimming in a river or the ocean, sitting under the shade of large trees, or fanning themselves with large leaves – they also made shelters in the cool depths of large caves and, later on, built shelters using stilts and other ingenious architectural devices so that they could capture breezes that blew low to the ground. While our ancestors were ingenious when it came to keeping cool in the sweltering heat, they did not have near the technology we have today, of course. Except for one particular technology first found in use in ancient Persia and still in use in modern day homes today – the evaporative cooler.
Evaporative coolers, devices which are sometimes called swamp coolers (perhaps due to the muddy smell associated with early coolers), air coolers, or desert coolers (due to the area in which they are the most use), are cooling devices that cool air in a very simple way – through the evaporation of water. Unlike a modern air conditioner which would be installed by a heating, air conditioning and ventilation (HVAC) professional ,evaporative coolers do not use what we think of as the very modern cooling techniques of refrigeration or absorption cooling.
Interesting enough, while evaporative coolers often have the interesting nickname “swamp cooler,” these cooling devices are often used not in the hot, muggy swamp but in areas that are dry and lack humidity. For instance, in the United States, evaporation coolers are most useful in areas such as the West. Cities like Denver, Colorado, Albuquerque, New Mexico, El Paso, Texas, and Phoenix and Tucson, Arizona would all benefit from the cooling methods used by the evaporative cooler. On the other hand, residents of cities which are actually swampy, such as New Orleans, Louisiana, Biloxi, Mississippi or Mobile, Alabama would not get much use at all out of an evaporative cooler.
Evaporative coolers capitalize on an interesting process in nature whereby surfaces that come into contact with evaporating water are actually cooled by that water.
Though our earliest ancestors did not adopt the principals of evaporative cooling, people in the U.S. have been applying for patents on evaporative coolers for more than 100 years, starting in the year 1906. Not only were these earliest evaporative coolers used to cool the air and give our ancestors in the western part of the United States a much needed break from the hot summer and desert air, they were also actually used to add a bit of humidity to the air. Old western beauty queens were certainly happy to add humidity to the dry desert air, as humidity keeps lovely faces and long limbs looking more beautiful and less strained.
Evaporative coolers have many uses aside from cooling residential homes and keeping moisture in the air for old fashioned beauty queens. They are also used in industrial settings where what we now consider a more traditional HVAC system may not be ideal. It would not be surprising if developing countries used some version of an evaporative cooler in their factories and plants.
One of the perks of evaporative coolers is their relatively low cost when compared to traditional refrigeration or absorption air conditioning. According to one source, they can cost as little as 80% as much as cooling using a traditional electric air conditioning method.