The expansion of air-conditioning was not just due to technological improvements in the systems or units that we have explored earlier. It was also dependent on the socio-technical construction of comfort.
In his book The Invention of Comfort, John Crowley argues that our understandings of comfort in material culture have “depended too uncritically on naturalistic assumptions that are liable to be unhistorical, ethnocentric, and teleological” (Crowley 2001, ix). He notes that the notion of comfort as physical comfort, in terms of a self-conscious satisfaction with the relationship between one’s bodies and its physical environment, was an Anglo-American innovation that first emerged in the 18th century material culture. Prior to that, comfort was primarily a moral term. Extending Crowley’s insight to air-conditioning, we shall question the naturalistic assumptions behind the accounts that attribute the global ubiquity of air-conditioning from late 20th century onward to its fulfillment of human beings’ innate desire for thermal comfort.
Before we discuss the construction of thermal comfort, let us briefly look at the “discovery” of thermal discomfort. Prior to the mid-19th century, physical discomfort in a crowded room was attributed to the concentration of miasma or poisonous vapors in the room that human bodies were deemed to produce through respiration. In the mid-19th century, Antoine-Laurent Lavoisier and Max von Pettenkofer attributed such discomfort to “excess of carbon dioxide” and “organic matter exhaled” respectively. However, in the early 20th century, Leonard Hill and his colleagues demonstrated that the discomfort was caused by atmospheric heat and humidity, and the discomfort could be alleviated by air movement (Bedford 1961).
There were two traditions of understanding thermal comfort. The first was associated with Leonard Hill and his fellow British industrial physiologists like H M Vernon, Thomas Bedford and Gordon Crowden. They studied thermal comfort of workers in field conditions, particularly work places with high thermal stress. Their early works were associated with two organizations – the 1916 Health of Munition Workers Committee and the 1918 Industrial Fatigue Research Board. The industrial physiologists found from their field research that the desirable thermal conditions were those varying and diverse, rather than uniform and monotonous. Their construction of thermal comfort differed fundamentally from that of the second tradition that we shall discuss next.
The second tradition of understanding thermal comfort was linked to the air-conditioning and ventilating engineers and their associates who studied thermal comfort in controlled laboratory conditions, such as the comfort chambers established by ASHVE (American Society of Heating and Ventilating Engineers) and its successor ASHAE (American Society of Heating and Air-conditioning Engineers). Key figures in this tradition included C P Yaglou, E Vernon Hill and F C Houghton. These researchers conducted their experiments in hermetically sealed comfort chambers, where temperature, humidity and air movement were varied using equipment similar to those manufactured by the air-conditioning industry. Thus, it is not surprising that their findings for thermal comfort conditions were directly opposite to those discovered by the Industrial physiologists. Rather than thermal diversity and variety, the ASHVE and ASHAE researchers recommended thermal monotony and steady-state conditions for comfort.
Within these laboratories, the physiological responses of the experimental subjects – typically young white males – were measured against different environmental conditions in the thermal chamber. Underpinning these experiments was a mechanistic and reductive understanding of thermal comfort as heat regulation (Murphy 2006).
According to Gail Cooper, thermal comfort not only defined the ideal indoor environment, “implicitly it also defined the ideal natural climate. Natural climate could be judged by the number of days that provided temperature and humidity within the comfort zone. The work of laboratories allowed air-conditioning manufacturers to replace the model natural climate of the seaside town or mountain resort with an ideal climate expressed in quantitative terms. Against such perfection, no natural climate could compete… When natural climate was ideal, mechanical systems sometimes fell short; but when quantitative standards of human comfort became the measure, natural climate was found wanting” (Cooper 1998, 79).