The enduring impact of swamp coolers in the Southwest United States

Before the rise of air conditioning in the United States, people in the Southwest faced intense heat daily. To cope, they adopted creative methods for relief. Some slept outside under damp sheets, while others adjusted work schedules to avoid the midday sun.

An effective cooling method, known as the “swamp cooler,” emerged as a solution. This technique dates back to ancient civilizations that fanned air over water in clay pots. The concept was refined in the early 20th century in the U.S. The result was the evaporative cooler or swamp cooler.

Oscar Palmer developed America’s first evaporative cooling system in 1908 in Arizona. The device works simply by pulling hot air through water-saturated pads. As the air passes through, it cools and humidifies before being directed indoors. This system was notable at the University of California Davis, as seen in a greenhouse demonstration.

By the 1930s, swamp coolers transformed large areas of the Southwest, cooling states like New Mexico and Nevada. Even today, despite the prevalence of air conditioning, they remain crucial in making desert-like areas more habitable. Eric Verpolegen, founder of CoolVeg, highlights their effectiveness in dry regions such as Arizona.

Traditional air conditioning became standard in the U.S. in the 1950s, with central air still considered a luxury for many. Evaporative coolers offer a low-cost and energy-efficient alternative where climate conditions permit. Ankit Kalanki from RMI underscores their benefits in suitable environments. However, high humidity renders them less effective, as the air cannot absorb more moisture.

Innovators are developing hybrid solutions to manage humidity and maximize cooling. Kalanki points out these efforts lead to more comprehensive cooling systems. Swamp coolers remain vital for many Americans and global citizens without access to other cooling technologies.

Verpolegen emphasizes the ongoing challenge of increased energy use and greenhouse gas emissions as temperatures rise. Palmer’s technology, alongside newer innovations, plays a crucial role in tackling this energy dilemma.

This article is part of “American Objects,” a series celebrating the 250th anniversary of the United States.