Oliver Evans: An Innovator in Vapor Compression for Refrigeration

All great inventors are problem solvers. From Benjamin Franklin with his bifocals to Johannes Gutenberg and his printing press, necessity is almost always the mother of invention. Such was the case with Oliver Evans, an often overlooked 18th-century inventor who made remarkable contributions to the industrial process in early America. With an aim toward reducing the human labor needed for manufacturing, Evans created the first fully-automated production line. He also introduced the first high-pressure steam engine. But his most important idea may have been one he never fully realized.

Vapor Compression

As impressive as his steam engine and production line were, those inventions were products of their time. But when it came to vapor compression, Evans was so far ahead of the curve that his idea would not become a reality for many years. According to historians, the middle-aged inventor described a closed vapor compression system in detail in 1805. With the help of ether sealed in a vacuum, the conceptual system would produce ice during the refrigeration cycle. More than a decade after the inventor’s death in 1919, another American innovator, Jacob Perkins, built the world’s first working vapor-compression refrigeration system.

The Science

Just as he had done in other fields, Oliver Evans wanted to create a fully-automated system that operated without human involvement. His vapor compression refrigeration system could run continuously with the help of a circulating liquid refrigerant that removed heat from the interior space. Based on his design details, Jacob Perkins created a closed-cycle system that included a gas compressor, a condenser, an evaporator, and an expansion valve. These four main components created cooler interior temperatures by forcing the refrigerant to change thermodynamic states. These transformations invariably produced heat, which was then removed from the environment, producing cooler temperatures.

Applications

Even though he was a visionary inventor, there was no way Oliver Evans could have possibly foreseen the impact his idea would have on numerous industries and scientific fields. More than two hundred years after he described it, vapor compression remains the most widely used method for air conditioning indoor and enclosed spaces. Hotels, hospitals, shopping malls, restaurants, movie theaters, private homes, even automobiles rely on it. As the most popular method of refrigeration, it is also used in both commercial and domestic refrigerators, warehouses that store food and meats, and in refrigerated trucks and railroad cars. Vapor compression refrigeration systems are even used in petroleum refineries, chemical plants, natural gas processing facilities, and many other industrial plants.

Hot and Cold Versatility

Although there are other refrigeration cycles that could take its place, few are as versatile as vapor compression. Not only is it used for indoor air conditioning, it is also needed to keep foods cold and to freeze them. The system is even used to produce heat for residential and commercial buildings. How? By essentially reversing the refrigeration cycle, vapor compression can heat an indoor space with a heat pump.

Even though it took the efforts of another inventor working a decade later to bring Evans’ idea to fruition, his contribution helped make the use of refrigeration systems widespread. For this reason, vapor compression is arguably the most important contribution to science Oliver Evans ever made.