Nation’s First Air Conditioned Office Building Built in Texas

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Are you a Texan who is in an emotional relationship with air conditioning? If you answered yes, then you should know the United States’ first high-rise, air-conditioned office building (including the basement) was in San Antonio, in the Milam Building. At a sturdy 21 stories, this downtown structure is named after a figure of the Republic of Texas and sports only the Lone Star flag at its crown. It was also the tallest brick and concrete-reinforced structure in the United States at the time of opening.

Chill build

Photo: Facebook/Dmitry Lisenko

The Milam Building originally toted an air-conditioning system installed by Carrier Engineering Corporation. Willis Carrier had invented modern air-conditioning twenty-six years earlier in New York, although not originally intended for human comfort but for humidity control. Introduced to the public in 1925, Carrier continued their promise in Texas after studying local temperatures and determining that a 75 degrees Fahrenheit (24 degrees Celcius) constant temperature at 56 percent relative humidity was best for San Antonio locals. This required unique technology in the original construction to allow ducts to deliver controlled air-handling throughout the building. Modeled from a German mine shaft compressor, large ice chunks were deposited in the building’s basement to aid the chilling unit.

Ice age

Photo: Facebook/Isbudet.se

Although some smaller single-story buildings such as stores, auditoriums, and theaters had been air-conditioned earlier, this structure required additional engineering. With 11 entities of equipment, two refrigeration units, and water storage tanks, pumps, and piping, the majority of the operational parts were located in the bowels of the building. The 18-foot-long chiller was updated in 1945 and remained in service until October 1989, a total of 60 years! The “manufactured weather” had additional benefits such as tenant retention, elimination or reduction of unwanted environmental elements, and for the owners, a rental premium of 10 to 15 percent more could be charged. This innovation to San Antonio only aided in its growth as a city and expanded its presence on a global stage. Enjoy the chill!