In 1928, air conditioning pioneer Willis Carrier figured out how to get chilled air into into a skyscraper when the 21-story Milam Building in San Antonio opened with a built-in Carrier “Manufactured Weather” system. But while department stores and banks were often mechanically cooled by the 1920s, relatively few prewar employers saw the value of what was then called comfort cooling, which was seen as a luxury amenity unfit for the office; 1930s New York City office towers like the Chrysler Building and the Empire State Building opened without central air.
Under such conditions, indoor workers were routinely just sent home in hot spells. Employers relied on a formula to determine when conditions were too oppressive, historian Gail Cooper wrote in her 1998 book Air Conditioning America: “When the temperature plus 20 percent of the humidity reached 100 or more, everyone gave up and went home.”
That happened with some frequency in places like swampy Washington, DC. Those who didn’t need to clock in left the city entirely during warmer months, decamping for summer homes in the countryside. Lawmakers did too, vacating the District in June and returning in the autumn — a much-mourned political traditionthat began to fade after air conditioning was installed in both houses of Congress in 1929. The White House and other government facilities soon followed, as the General Services Administration began incorporating AC into into New Deal-era federal office buildings, making DC what was likely the most air-conditioned city in the world at the end of the 1930s.
To encourage more employers to follow suit, the nascent HVAC industry showed off 1946 studies indicating that typists transferred to air-conditioned offices boosted their output by 24%. Efficiency and productivity, rather than personal comfort, became the technology’s big selling point, and trade publications touted surveys showing that workers preferred artificially cooled and filtered air, even in places with mild climates. “It is a great help to non-smokers who must work between inveterate smokers all day,” one worker in a Minneapolis office enthused in 1937.
A run of hot summers in the early 1950s further helped convince property owners and local officials that AC was a must for offices, hospitals and public buildings. The record-shattering 1954 heat wave in the Midwest forced authorities in St. Louis and Kansas City to close offices and postpone meetings and trials. Sales of portable window-unit air conditioners — then a new consumer product — surged.