The Enduring Legacy of Swamp Coolers in the Southwest
Before air conditioning became widespread in the United States, the Southwest faced intense heat. People often resorted to creative methods to cope with the sweltering weather. Some would sleep outdoors under damp sheets. Others adjusted their routines, avoiding outdoor work during peak sunlight hours.
Then, a new solution emerged: the swamp cooler. This device, rooted in basic cooling principles from ancient civilizations, offered relief. In early cultures, air was fanned over water in clay pots. This concept was refined in the United States in the early 20th century, resulting in the evaporative cooler.
Oscar Palmer perfected the first American evaporative cooling system in 1908 in Arizona. The mechanism is simple: a fan draws hot air through water-soaked, porous pads. This process cools and humidifies the air before it is directed indoors. A practical example involves a greenhouse at the University of California Davis using this technology effectively.
By the 1930s, swamp coolers transformed regions, cooling areas in New Mexico and Nevada. Despite the dominance of air conditioning, these coolers remain vital in deserts. “In Arizona, dry conditions enhance cooling effects,” says Eric Verpolegen, founder of CoolVeg, a nonprofit focused on evaporative cooling for produce.
Modern traditional air conditioning became common in the 1950s and remains a luxury for some. Swamp coolers still offer low-cost, energy-efficient solutions. “Where climate permits, evaporative coolers are viable where traditional air conditioning isn’t present,” notes Ankit Kalanki from RMI, a clean energy nonprofit.
Swamp coolers and fans struggle in humid regions. Saturated air limits effectiveness. “Innovation is underway, combining evaporative cooling with systems to manage humidity,” Kalanki explains, creating hybrid solutions.
Evaporative coolers serve both Americans and those globally lacking access to modern cooling. “A cycle exists: hotter weather increases cooling needs, raising energy use and potential greenhouse gas emissions,” Verpolegen highlights. This underlines the significance of both Palmer’s invention and modern advancements.
Part of the “American Objects” series, this piece commemorates the 250th anniversary of the United States. For more in this series, click here. For more anniversary stories, click here.
Alexa St. John is an Associated Press climate reporter. Follow her on X: @alexa_stjohn. For contact, email [email protected].