Nowadays most of us are lucky enough to live our lives in comfortable surroundings. Whether in our homes or in an office, we can rely on being comfortably cool when the sun blazes outside or pleasantly warm when ice clings to our doorstep. We just don't think about it. We take our comforts for granted, yet it wasn't always like that. In a large and geographically diverse country like the United States, people were once at the mercy of the extremes of the weather. Stifling hot Summers were almost as unpleasant as freezing cold Winters. All our ancestors could do to protect themselves was either to seek an imperfect sanctuary in a shady place or huddle round the fireplace. That was until one man decided to apply himself to the problem, and what he came up with ultimately transformed our lives.
Willis Haviland Carrier was born in the town of Angola, New York, on the shores of Lake Eyrie, on November 26th 1876. He was an only child who would amuse himself - aided by strong encouragement from his mother - by using his inquiring mind and love of mathematics to solve endless problems of his own devising, both technical and scientific. He would later describe his passion for practicality by saying, "I fish only for edible fish, and hunt only for edible game even in the laboratory." From an early age he harbored an ambition to be an engineer and that ambition was realized when he received a scholarship to study at Cornell University where he graduated in 1901 with a masters degree in mechanical engineering.
After graduation he secured a job with the Buffalo Forge Company - who manufactured heaters and blowers - for the princely sum of $10 a week. Ever the innovator, Carrier soon set about doing his own research into the heat-holding capacity of air when blown over heated pipes. His work allowed the company to calculate how much heater surface area was needed to heat a given space and, consequently, make significant efficiency savings in their designs. In gratitude for their young engineer's efforts the company put him to work in a new experimental science department.
His first task was to solve the humidity problems at a printing plant in New York City. Fluctuations in heat and humidity at the plant were causing the paper in the printing presses to expand and contract thereby distorting the application of the ink. Carrier had always insisted that the way to solve problems was to break them down into easily manageable segments and that is how he applied himself to the printer problem. He understood that what was required was a uniform humidity level throughout the printing room. He found out what the correct moisture level for printing should be and the correct temperature to maintain that level. By working with air-movement levels and water temperatures in refrigeration coils he was able to work out a system to maintain a constant temperature and humidity and solve the printer's problem. Carrier had created the first scientific air conditioning system.
He quickly developed his ideas and constructed other mechanisms to control humidity and heat. It is said that Carrier had his 'eureka' moment while standing on a railroad platform in Pittsburgh contemplating the city smog and what caused it. That inspiration led, in 1906, to his patenting an 'Apparatus for Treating Air' (the patent immediately before it on the list was for a 'Flying Machine', designed by two brothers called Orville and Wilbur Wright. Those were heady times).
Carrier's new air conditioning system utilized two principles: Refrigeration (to control temperature) and dew-point control (to control humidity). For refrigeration, ammonia gas is compressed (and so heated) and forced our at high pressure through metal coils where it dissipates some of that heat and condenses into liquid. It passes through an expansion valve, on the other side of which is an area of lower pressure (the compressor is sucking the liquid through), the liquid boils and vaporizes (ammonia has a very low boiling point, -27 F) and heat in the air surrounding the pipe is absorbed. The cool gas returns to the compressor and the cycle repeats. The dew-point is the temperature that a parcel of air must be cooled to for water vapor to condense into water. Carrier was able to control temperature and humidity by a system using chilled pipes and a controllable fine water spray.
He soon began to design air conditioning systems for hotels, office buildings, hospitals and factories. Those early units were large and expensive and also quite hazardous because they used highly toxic ammonia as a refrigerant (coolant). In 1911 Carrier presented his 'Rational Psychometric Formula' to the American Society of Mechanical Engineers, a formula still used today by the air conditioning industry.
In 1915 he and six colleagues invested their savings in a new company, The Carrier Engineering Corporation, and the development of air conditioning gathered pace. The company set about improving the efficiency and practicality of its units and in the early 1920's two major breakthroughs were made: In 1921 Carrier developed a more practical method of pumping the refrigerant by replacing the old piston pumps with centrifugal pumping blades. This allowed for the air conditioning of larger spaces and thereby increased the scope of the company's market. Improved designs also led to the manufacture of small units and the exploitation of the other end of the market: Shops and department stores. The first store to use a Carrier centrifugal system was the J. L. Hudson Department Store in Detroit. The customers were delighted!
Another breakthrough came with the replacement of the highly toxic ammonia with a safer alternative, dielene. Now Carrier Corp could think about introducing air conditioning into private homes. By the late 1920's, the company had developed its first purpose built home conditioner, the "Weathermaker".
Air conditioning led to a transformation in the American demographic. Comfortable living was now possible in states in the South and West that had previously been plagued by the extremes of heat and humidity. People could now be comfortable wherever they lived and worked and whatever the time of year and by the 1950's many people were moving to the previously inhospitable states of Arizona and Nevada.
By the outbreak of WWII all the major buildings and institutions of the US had been air conditioned, including the White House and the chambers of the Senate and the House of Representatives. All forms of transport would soon be made comfortable - including trains, buses, automobiles, aircraft, even submarines - and industry was transformed. Working conditions were stabilized and foodstuffs and other commodities could be produced and stored like never before.
Willis Carrier died in 1950 at the age of 73. It is interesting that Carrier and the Wright brothers shared a place on the patent list of 1906 because they were very similar men and both their inventions transformed how we live. The Wright brothers went down in history but Willis Carrier remains relatively unknown. However, the ability to control our personal environment has completely revolutionized the way we live our day to day lives and because it was Willis Carrier who methodically and brilliantly put air conditioning into practice we should gladly honor his memory.